The development of highly active catalysts is the key to the successful application of sulfate radical(SO_(4)^(·-))-based advanced oxidation processes(AOPs)to wastewater treatment.Herein,bimetallic oxide CoMn_(2)...The development of highly active catalysts is the key to the successful application of sulfate radical(SO_(4)^(·-))-based advanced oxidation processes(AOPs)to wastewater treatment.Herein,bimetallic oxide CoMn_(2)O_(4)hierarchical porous nanosheets(CoMn_(2)O_(4)HPNSs)were constructed using glucose/urea deep eutectic solvent(DES)as sustainable solvent and self-formed sacrificial carbon templates.The prepared CoMn_(2)O_(4)HPNS exhibited outstanding peroxymonosulfate(PMS)activation performance,achieving the rapid degradation of refractory organic compounds in wastewater,including 5-sulfosalicylic acid(100%),acetaminophen(100%),oxtetracycline(100%),and sulfamethoxazole(91%)within 20 min.This excellent performance was attributed not only to the synergistic catalytic effect of Co-Mn bimetals,but also to the hierarchical porous structure which exposes more active sites and accelerates the migration of PMS and organic pollutants.In addition,CoMn_(2)O_(4)HPNS also showed excellent reusability and high stability in multiple cycles of degradation.The active species quenching results and electron paramagnetic resonance measurements revealed that SO_(4)^(·-)greatly contributed to organic degradation,while^(1)O_(2)and·OH also involved.Moreover,a series of other transition metal oxides(Co_(3)O_(4),Fe_(2)O_(3),Mn_(3)O_(4),NiO,and CoFe_(2)O_(4))with hierarchical porous nanosheet structures were successfully fabricated with this method.This study provides a simple,general,and low-cost strategy for fabricating hierarchical porous transition metal oxides,which are promising for the environmental remediation or many other applications in the future.展开更多
Two-dimensional porous nanosheet heterostructure materials,which combine the advantages of both architecture and components,are expected to feature a significant photocatalytic performance toward CO_(2) conversion int...Two-dimensional porous nanosheet heterostructure materials,which combine the advantages of both architecture and components,are expected to feature a significant photocatalytic performance toward CO_(2) conversion into useful fuels.Herein,we provide a facile strategy for fabricating sulfur-doped C_(3)N_(4) porous nanosheets with embedded SnO_(2)-SnS_(2) nanojunctions(S-C_(3)N_(4)/SnO_(2)-SnS_(2))via liquid impregnation-pyrolysis and subsequent sulfidation treatment using a layered supramolecular structure as the precursor of C_(3)N_(4).A hexagonal layered supramolecular structure was first prepared as the precursor of C_(3)N_(4).Then Sn^(4+) ions were intercalated into the supramolecular interlayers through the liquid impregnation method.The subsequent annealing treatment in air simultaneously realized the fabrication and efficient exfoliation of layered C_(3)N_(4) porous nanosheets.Moreover,SnO_(2) nanoparticles were formed and embedded in situ in the porous C_(3)N_(4) nanosheets.In the following sulfidation process under a nitrogen atmosphere,sulfur powder can react with SnO_(2) nanoparticles to form SnO_(2)-SnS_(2) nanojunctions.As expected,the exfoliation of sulfur-doped C_(3)N_(4) porous nanosheets and ternary heterostructure construction could be simultaneously achieved in this work.Sulfur-doped C_(3)N_(4) porous nanosheets with embedded SnO_(2)-SnS_(2) nanojunctions featured abundant active sites,enhanced visible light absorption,and efficient interfacial charge transfer.As expected,the optimized S-C_(3)N_(4)/SnO_(2)-SnS_(2) achieved a much higher gas-phase photocatalytic CO_(2) reduction performance with high yields of CO(21.68μmol g^(−1)h^(−1))and CH_(4)(22.09μmol g^(−1)h^(−1))compared with the control C_(3)N_(4),C_(3)N_(4)/SnO_(2),and S-C_(3)N_(4)/SnS_(2) photocatalysts.The selectivity of CH_(4) reached 80.30%.Such a promising synthetic strategy can be expected to inspire the design of other robust C_(3)N_(4)-based porous nanosheet heterostructures for a broad range of applications.展开更多
Simultaneously integrating mesocrystalline stacking superstructures,porous nanosheets and defective oxygen vacancies(OVs)into BiOCl crystals is an available strategy to enhance the visible-light-driven photocatalytic ...Simultaneously integrating mesocrystalline stacking superstructures,porous nanosheets and defective oxygen vacancies(OVs)into BiOCl crystals is an available strategy to enhance the visible-light-driven photocatalytic activity.Herein,we report a facile etching agent-assisted hydrothermal approach to achieve one-pot fabrication of mesocrystalline BiOCl porous nanosheet stacking superstructures with defective OVs,which show high catalytic activities towards to the visible-light-driven degradation of organic dyes.The formation of stacking superstructure in a mesocrystalline BiOCl is responsibility for increasing the transport of charge carriers.Experimental results and theoretical calculations suggest that the presence of OVs is beneficial to tuning the energy band structure for the improvement of visible light harvesting,prolonging the lifetime and enhancing the oxidation activity of photogenerated charge carriers.Additionally,the porous morphology and thin nanosheet building block could supply abundant active sites for photocatalysis.This research might arouse in-depth investigations on the development of novel precursor-modified strategy for the synthesis of high-active BiOX(X¼Cl,Br and I)-based photocatalysts.展开更多
Carbon materials have shown remarkable usefulness in facilitating the performance of insulating sulfur cathode for lithium–sulfur batteries owing to their excellent conductivity and porous structure. However,the anxi...Carbon materials have shown remarkable usefulness in facilitating the performance of insulating sulfur cathode for lithium–sulfur batteries owing to their excellent conductivity and porous structure. However,the anxiety is the poor affinity toward polar polysulfides due to the intrinsic nonpolar surface of carbon.Herein, we report a direct pyrolysis of the mixture urea and boric acid to synthesize B/N–codoped hierarchically porous carbon nanosheets(B–N–CSs) as efficient sulfur host for lithium–sulfur battery. The graphene–like B–N–CSs provides high specific surface area and porous structure with abundant micropores(1.1 nm) and low–range mesopores(2.3 nm), thereby constraining the sulfur active materials within the pores. More importantly, the codoped B/N elements can further enhance the polysulfide confinement through strong Li–N and B–S interaction based on the Lewis acid–base theory. These structural superiorities significantly suppress the shuttle effect by both physical confinement and chemical interaction, and promote the redox kinetics of polysulfide conversion. When evaluated as the cathode host, the S/B–N–CSs composite displays the excellent performance with a high reversible capacity up to 772 m A h g–1 at 0.5 C and a low fading rate of ^0.09% per cycle averaged upon 500 cycles. In particular, remarkable stability with a high capacity retention of 87.1% can be realized when augmenting the sulfur loading in the cathode up to 4.6 mg cm^(-2).展开更多
Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in photo-catalysis.Nevertheless,it often suffers from moderate photo-catalytic activity due to its low specific surfac...Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in photo-catalysis.Nevertheless,it often suffers from moderate photo-catalytic activity due to its low specific surface area and fast recombination rate of photogenerated electrons upon photo-excitation.Herein,we overcome the bottlenecks by constructing a porous g-C_(3)N_(4) nanosheet(PCNS)through a simple thermal oxidation etching method.Benefited from its porous layer structure,the obtained PCNS exhibits large specific surface area,efficient separation of photogenerated charge carriers,as well as high exposure of active sites.As a result,it is robust and universal in visible light-driven dehydrogenation of alcohols in water under oxidant-free condition.Almost quantitative yields(>99%)of various valuable carbonyl compounds were obtained over PCNS,while bulk g-C_(3)N_(4) was far less efficient.Moreover,the photo-catalyst was highly stable and could be facilely recovered from the aqueous system for efficient reuse.The easy preparation and excellent performance made PCNS a promising and competitive photocatalyst for the solar applications.展开更多
The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption capability.Herein,instead of anch...The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption capability.Herein,instead of anchoring on carbon materials in single layer,MoS_(2) flower-like microspheres were stacked on the surface of pomelo peels-derived porous carbon nanosheets(C)to fabricate MoS_(2)@C nanocomposites by a facile solvothermal process.EM wave absorption performances of MoS_(2)@C nanocomposites in X-band were systematically investigated,indicating the minimum reflection loss(RLmin)of-62.3 dB(thickness of 2.88 mm)and effective absorption bandwidth(EAB)almost covering the whole X-band(thickness of 2.63 mm)with the filler loading of only 20 wt.%.Superior EM wave absorption performances of MoS_(2)@C nanocomposites could be attributed to the excellent impedance matching characteristic and dielectric loss capacity(conduction loss and polarization loss).This study revealed that the as-prepared MoS_(2)@C nanocomposites would be a novel prospective candidate for the sustainable EM absorbents with superior EM wave absorption performances.展开更多
Metal-nanocluster materials have gradually become a promising electrode candidate for supercapaci-tor application.The high-efficient and rational architecture of these metal-nanocluster electrode mate-rials with satis...Metal-nanocluster materials have gradually become a promising electrode candidate for supercapaci-tor application.The high-efficient and rational architecture of these metal-nanocluster electrode mate-rials with satisfied supercapacitive performance are full of challenges.Herein,Fe-nanocluster anchored porous carbon(FAPC)nanosheets were constructed through a facile and low-cost impregnation-activation strategy.Various characterization methods documented that FAPC nanosheets possessed a mesopore-dominated structure with large surface area and abundant Fe-N4 active sites,which are crucial for su-percapacitive energy storage.The optimal FAPC electrode exhibited a high specific capacitance of 378 F/g at a specific current of 1 A/g and an excellent rate capability(271 F/g at 10 A/g),which are comparable or even superior to that of most reported carbon candidates.Furthermore,the FAPC-based device achieved a desired specific energy of 14.8 Wh/kg at a specific power of 700 W/kg.This work opens a new avenue to design metal-nanocluster materials for high-performance biomass waste-based supercapacitors.展开更多
The performance of catalyst depends on the intrinsic activity of active sites and the structural characteristics of the support.Here,we simultaneously integrate single nickel(Ni)sites and platinum-nickel(PtNi)alloy na...The performance of catalyst depends on the intrinsic activity of active sites and the structural characteristics of the support.Here,we simultaneously integrate single nickel(Ni)sites and platinum-nickel(PtNi)alloy nanoparticles(NPs)on a two-dimensional(2D)porous carbon nanosheet,demonstrating remarkable catalytic performance in the oxygen reduction reaction(ORR).The single Ni sites can activate the oxygen molecules into key oxygen-containing intermediate that is further efficiently transferred to the adjacent PtNi alloy NPs and rapidly reduced to H_(2)O,which establishes a relay catalysis between active sites.The porous structure on the carbon nanosheet support promotes the transfer of active intermediates between these active sites,which assists the relay catalysis by improving mass diffusion.Remarkably,the obtained catalyst demonstrates a half-wave potential of up to 0.942 V,a high mass activity of 0.54 A·mgPt^(−1),and negligible decay of activity after 30,000 cycles,which are all superior to the commercial Pt/C catalysts with comparable loading of Pt.The theoretical calculation results reveal that the obtained catalyst with defect structure of carbon support presents enhanced relay catalytic effect of PtNi alloy NPs and single Ni sites,ultimately realizing improved catalytic performance.This work provides valuable inspiration for developing low platinum loading catalyst,integrating single atoms and alloy with outstanding performance in fuel cell.展开更多
The Pt-free photocatalytic hydrogen evolution(PHE)has been the focus in the photocatalytic field.The catalytic system with the large accessible surface and good mass-transfer ability,as well as the intimate combinatio...The Pt-free photocatalytic hydrogen evolution(PHE)has been the focus in the photocatalytic field.The catalytic system with the large accessible surface and good mass-transfer ability,as well as the intimate combination of co-catalyst with semiconductor is promising for the promotion of the application.Here,we have reported the design of the two-dimensional(2D)porous C_(3)N_(4)nanosheets(PCN NS)intimately combined with few-layered MoS_(2)for the high-effective Pt-free PHE.The PCN NS were synthesized based on peeling the melamine–cyanuric acid precursor(MC precursor)by the triphenylphosphine(TP)molecular followed by the calcination,mainly due to the matched size of the(100)plane distance of the precursor(0.8 nm)and the height of TP molecular.The porous structure is favorable for the mass-transfer and the 2D structure having large accessible surface,both of which are positive to promote the photocatalytic ability.The few-layered MoS_(2)are grown on PCN to give 2D MoS_(2)/PCN composites based on anchoring phosphomolybdic acid(PMo_(12))cluster on polyetherimide(PEI)-modified PCN followed by the vulcanization.The few-layered MoS_(2)have abundant edge active sites,and its intimate combination with porous PCN NS is favorable for the faster transfer and separation of the electrons.The characterization together with the advantage of 2D porous structure can largely promote the photocatalytic ability.The MoS_(2)/PCN showed good PHE activity with the high hydrogen production activity of 4,270.8μmol·h^(−1)·g^(−1)under the simulated sunlight condition(AM1.5),which was 7.9 times of the corresponding MoS_(2)/bulk C_(3)N_(4)and 12.7 times of the 1 wt.%Pt/bulk C_(3)N_(4).The study is potentially meaningful for the synthesis of PCN-based catalytic systems.展开更多
Owing to the complexity of electron transfer pathways,the sluggish oxygen evolution reaction process is defined as the bottleneck for the practical application of Zn-air batteries.In this effort,metal nanoparticles(Co...Owing to the complexity of electron transfer pathways,the sluggish oxygen evolution reaction process is defined as the bottleneck for the practical application of Zn-air batteries.In this effort,metal nanoparticles(Co,Ni,Fe,etc.)encapsulated within nitrogen-doped carbon materials with abundant edge sites were synthesized by one-step pyrolysis treatment using cigarette butts as raw materials,which can drastically accelerate the overall rate of oxygen evolution reaction by facilitating the adsorption of oxygenated intermediates by the edge-induced topological defects.The prepared catalyst of nitrogen-doped carbon porous nanosheets loaded with Co nanoparticles(Co@NC-500)exhibits enhanced catalytic activity toward oxygen evolution reaction,with a low overpotential of 350 mV at the current density of 10 mA·cm^(-2).Furthermore,the Zn-air battery assembled with Co@NC-500 catalyst demonstrates a desirable performance affording an open-circuit potential of 1.336 V and power density of 33.6 mW·cm^(-2),indicating considerable practical application potential.展开更多
Catalysts for the oxygen reduction reaction （ORR） play an important role in fuel cells. Alternative non-precious metal catalysts with comparable ORR activity to Pt-based catalysts are highly desirable for the develo...Catalysts for the oxygen reduction reaction （ORR） play an important role in fuel cells. Alternative non-precious metal catalysts with comparable ORR activity to Pt-based catalysts are highly desirable for the development of fuel cells. In this work, we report for the first time a spinel MnC0204/C ORR catalyst consisting of uniform MnC0204 nanoparticles cross-linked with two-dimensional （2D） porous carbon nanosheets （abbreviated as porous MnC0204/C nanosheets）, in which glucose is used as the carbon source and NaC1 as the template. The obtained porous MnCo204/C nanosheets present the combined properties of an interconnected porous architecture and a large surface area （175.3 m2-g-1）, as well as good electrical conductivity （1.15 x 102 S.cm-1）. Thus, the as-prepared MnC0204/C nanosheets efficiently facilitate electrolyte diffusion and offer an expedite transport path for reactants and electrons during the ORR. As a result, the as-prepared porous MnC0204/C nanosheet catalyst exhibits enhanced ORR activity with a higher onset potential and current density than those of its counterparts, including pure MnC0204, carbon nanosheets, and Vulcan XC-72R carbon. More importantly, the porous MnC0204/C nanosheets exhibit a com- parable electrocatalytic activity but superior stability and tolerance toward methanol crossover effects than a high-performance Pt/C catalyst in alkaline medium. The synthetic strategy outlined here can be extended to other non- precious metal catalysts for application in electrochemical energy conversion.展开更多
Spinel oxides containing Co and Ni are a promising substitute as a noble metal catalyst for methane combustion.Achieving a complete oxidation of methane under 400°C remains challenging,andhydrothermal 60 h NiClit...Spinel oxides containing Co and Ni are a promising substitute as a noble metal catalyst for methane combustion.Achieving a complete oxidation of methane under 400°C remains challenging,andhydrothermal 60 h NiClittle impact on activity,especially at high space velocities due to the long hydrothermal time with less absorbed oxygen species and crystal defects.Overall,these results help clarify methane activa-tion mechanisms and aid the development of more efficient low-cost catalysts.展开更多
Exploring efficient oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)electrocatalysts is crucial for developing water splitting devices.The composition and structure of catalysts are of great importan...Exploring efficient oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)electrocatalysts is crucial for developing water splitting devices.The composition and structure of catalysts are of great importance for catalytic performance.In this work,a heterogeneous Ru modified strategy is engineered to improve the catalytic performance of porous NiCo_(2)O_(4)nanosheets(NSs).Profiting from favorable elements composition and optimized structure property of decreased charge transfer barrier,more accessible active sites and increased oxygen vacancy concentration,the Ru-NiCo_(2)O_(4)NSs exhibits excellent OER activity with a low overpotential of 230 mV to reach the current density of 10 mA/cm^(2)and decent durability.Furthermore,Ru-NiCo_(2)O_(4)NSs show superior HER activity than the pristine NiCo_(2)O_(4)NSs,as well.When assembling Ru-NiCo_(2)O_(4)NSs couple as an alkaline water electrolyzer,a cell voltage of 1.60 V can deliver the current density of 10 mA/cm^(2).This work provides feasible guidance for improving the catalytic performance of spinel-based oxides.展开更多
Interfacial engineering is a powerful method to improve the bifunctional electrocatalytic performance of pure phase catalysts.While it is expected to further optimize the electronic configuration of heterojunctions to...Interfacial engineering is a powerful method to improve the bifunctional electrocatalytic performance of pure phase catalysts.While it is expected to further optimize the electronic configuration of heterojunctions to boost the reaction kinetics in hydrogen/oxygen evolution reaction(HER/OER),but remains a challenge.Herein,a novel in situ hybrid heterojunction strategy is developed to construct 2D porous Co-doped Ni/Ni_(3)N heterostructure nanosheets(Co-Ni/Ni_(3)N)by pyrolysis of partially cobalt substituted nickel-zeolitic imidazolate framework(CoNi-ZIF)nanosheets under NH3 atmosphere.A combined experimental and theoretical studies manifest that the hybrid heterostructures can display regulative electronic states and downshift d-band center from the Fermi level,as well as optimize the adsorption energy of reaction intermediates,thus reducing the thermodynamic energy barriers and accelerating the catalytic kinetics.Consequently,benefitting from the optimized electronic configuration,hierarchical hollow nanosheets architecture,and abundant doped heterojunctions,the hybrid Co-Ni/Ni_(3)N heterostructure catalyst exhibits efficient catalytic activity for both HER(60 mV)and OER(322 mV)at 10 mA cm^(-2)in alkaline media,which is 105 and 47 mV lower than that of pure Ni_(3)N,respectively.The electrochemically active surface area of Co-Ni/Ni_(3)N is two times higher than that of Ni3N.Furthermore,the coupled practical water electrolyzer requires a low voltage of 1.575 V to reach 10 mA cm^(-2),and it can be driven by a 1.5 V battery.This work highlights the interface engineering guidance for the rational establishment of hybrid interfaces by electronic modulation of interfacial effect for alkaline water splitting.展开更多
Unique two-dimensional(2D)porous nanosheets with overwhelmingly rich channels and large specific surface area exhibit superior electrochemical capacitance performance,as compared to the conventional zero-and one-dimen...Unique two-dimensional(2D)porous nanosheets with overwhelmingly rich channels and large specific surface area exhibit superior electrochemical capacitance performance,as compared to the conventional zero-and one-dimensional counterparts.As ternary transition metal sulfides(TMSs)are well recognized for their high electrochemical activity and capacity,and the replacement of oxygen with sulfur may result in high stability and flexible properties of the nanomaterials,as compared to transition metal oxides,herein we report the synthesis of 2D porous nanosheet arrays of Zn_(x)Co_(1-x)S(x=0,0.25,0.5,0.75,and 1)via a facile hydrothermal process.Due to the synergistic effect of the metal components and a unique 2D porous structure,the Zn_(0.5)Co_(0.5)S electrode was found to stand out as the best among the series,with a high specific capacity of 614 C g^(-1)at 1 A g^(-1)and excellent cycle retention rate of 90%over 10,000 cycles at 10 A g^(-1).Notably,a supercapattery based on a Zn_(0.5)Co_(0.5)S positive electrode and an activated carbon(AC)negative electrode(Zn_(0.5)Co_(0.5)S//AC)was found to display a 1.6 V voltage window,a 61 mA h g^(-1)specific capacity at 1 A g^(-1),a 49 Wh kg^(-1)energy density at 957 W kg^(-1)power density,and excellent cycling performance(88%over 10,000 cycles),suggesting tremendous potential of Zn_(0.5)Co_(0.5)S in the development of high-performance supercapattery devices.展开更多
Although molybdenum disulfide (MoS_(2))-based materials are generally known as active electrocatalysts for the hydrogen evolution reaction (HER), the inert performance for the oxygen evolution reaction (OER) seriously...Although molybdenum disulfide (MoS_(2))-based materials are generally known as active electrocatalysts for the hydrogen evolution reaction (HER), the inert performance for the oxygen evolution reaction (OER) seriously limits their wide applications in alkaline electrolyzers due to there exists too strong metal-sulfur (M−S) bond in MoS_(2). Herein, by means of surface reorganization engineering of bimetal Al, Co-doped MoS_(2) (devoted as AlCo_(3)-MoS_(2)) through in situ substituting partial oxidation, we successfully significantly activate the OER activity of MoS_(2), which affords a considerably low overpotential of 323 mV at −30 mA cm^(−2), far lower than those of MoS_(2), Al-MoS_(2) and Co-MoS_(2) catalysts. Essentially, the AlCo_(3)-MoS_(2) substrate produces lots of M−O (M=Al, Co and Mo) species with oxygen vacancies, which trigger the surface self-reconstruction of pre-catalysts and simultaneously boost the electrocatalytic OER activity. Moreover, benefiting from the moderate M−O species formed on the surface, the redistribution of surface electron states is induced, thus optimizing the adsorption of OH* and OOH* intermediates on metal oxyhydroxides and awakening the OER activity of MoS_(2).展开更多
Lithium-sulfur(Li-S)batteries have attracted significant attention for their high specific capacity,non-toxic and harmless advantages.However,the shuttle effect limits their development.In this work,small-sized tin di...Lithium-sulfur(Li-S)batteries have attracted significant attention for their high specific capacity,non-toxic and harmless advantages.However,the shuttle effect limits their development.In this work,small-sized tin disulfide(SnS_(2))nanoparticles are embedded between interlayers of twodimensional porous carbon nanosheets(PCNs),forming a multi-functional nanocomposite(PCN-SnS_(2))as a cathode carrier for Li-S batteries.The graphitized carbon nanosheets improve the overall conductivity of the electrode,and the abundant pores not only facilitate ion transfer and electrolyte permeation,but also buffer the volume change during the charge and discharge process to ensure the integrity of the electrode material.More importantly,the physical confinement of PCN,as well as the strong chemical adsorption and catalytic reaction of small SnS_(2)nanoparticles,synergistically reduce the shuttle effect of polysulfides.The interaction between a porous layered structure and physical-chemical confinement gives the PCN-SnS_(2)-S electrode high electrochemical performance.Even at a high rate of 2 C,a discharge capacity of 650 mA h g^(-1)is maintained after 150 cycles,underscoring the positive results of SnS_(2)-based materials for Li-S batteries.The galvanostatic intermittent titration technique results further confirm that the PCN-SnS_(2)-S electrode has a high Li+transmission rate,which reduces the activation barrier and improves the electrochemical reaction kinetics.This work provides strong evidence that reducing the size of SnS_(2)nanostructures is beneficial for capturing and reacting with polysulfides to alleviate their shuttle effect in Li-S batteries.展开更多
Recently,metal-based carbon materials have been verified to be an effective persulfate activator,but secondary pollution caused by metal leaching is inevitable.Hence,a green metalfree 3D macroscopic N-doped porous car...Recently,metal-based carbon materials have been verified to be an effective persulfate activator,but secondary pollution caused by metal leaching is inevitable.Hence,a green metalfree 3D macroscopic N-doped porous carbon nanosheets(NPCN)was synthesized successfully.The obtained NPCN showed high adsorption capacity of tetracycline(TC)and excellent persulfate(PS)activation ability,especially when calcined at 700℃(NPCN-700).The maximum adsorption capacity of NPCN-700 was 121.51 mg/g by H-bonds interactions.Moreover,the adsorption process followed pseudo-second-order kinetics model and Langmuir adsorption isotherm.The large specific surface area(365.27 mg/g)and hierarchical porous structure of NPCN-700 reduced the mass transfer resistance and increased the adsorption capacity.About 96.39%of TC was removed after adding PS.The effective adsorption of the catalyst greatly shortened the time for the target organic molecules to migrate to the catalyst.Moreover,the NPCN-700 demonstrated high reusability with the TC removal rate of 80.23%after 4 cycles.Quenching experiment and electron paramagnetic resonance(EPR)test confirmed the non-radical mechanism dominated by ^(1)O_(2).More importantly,the C=O groups,defects and Graphitic N acted as active sites to generate ^(1)O_(2).Correspondingly,electrochemical measurement revealed the direct electron transfer pathway of TC degradation.Finally,multiple degradation intermediates were recognized by the LC-MS measurement and three possible degradation pathways were proposed.Overall,the prepared NPCN had excellent application prospects for removal of antibiotics due to its remarkable adsorption and catalytic degradation capabilities.展开更多
Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.Howe...Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.However,the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading.In this work,a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoS_(x)material(CNS@MoS_(x)).This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3%and~100%Coulombic efficiency after 400 cycles at 1.2 A·g^(-1),much superior compared to bare MoS_(2).Density functional theory(DFT)calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoS_(x)are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoS_(x)via strong chemical bonding,enabling MoS_(x)to be firmly confined on the substrate.Moreover,this unique hierarchical complex structure ensures the fast migration of Zn^(2+)within MoS_(x)interlayer.展开更多
Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts...Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts the C–C bond cleavage.Inspired by the molecular orbital theory,we proposed the d-state-editing strategy to construct more unoccupied d-states of Pd for the enhanced interaction with CH_(3)CO^(*) to break C–C bonds.As expected,the reduced number of e_g electrons and more unoccupied d-states of Pd successfully formed on as-prepared porous Rh Au–Pd Cu nanosheets(PNSs).Theoretical calculations show that the optimized d-states of Rh Au–Pd Cu PNS can effectively improve the adsorption of CH_(3)CO^(*) and drastically reduce the energy barrier of C–C bond cleavage,thus boosting the complete oxidation of ethanol.The charge ratio of C_1 pathway on Rh Au–Pd Cu PNSs is 51.5%,more than 2 times higher than that of Pd NSs.Our finding provides an innovative perspective for the design of highly-efficient noble-based electrocatalysts.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.22074137 and 21721003)High Technology Industrialization Special of Science and Technology Cooperation of Jilin Province and the Chinese Academy of Sciences(No.2021SYHZ0036).
文摘The development of highly active catalysts is the key to the successful application of sulfate radical(SO_(4)^(·-))-based advanced oxidation processes(AOPs)to wastewater treatment.Herein,bimetallic oxide CoMn_(2)O_(4)hierarchical porous nanosheets(CoMn_(2)O_(4)HPNSs)were constructed using glucose/urea deep eutectic solvent(DES)as sustainable solvent and self-formed sacrificial carbon templates.The prepared CoMn_(2)O_(4)HPNS exhibited outstanding peroxymonosulfate(PMS)activation performance,achieving the rapid degradation of refractory organic compounds in wastewater,including 5-sulfosalicylic acid(100%),acetaminophen(100%),oxtetracycline(100%),and sulfamethoxazole(91%)within 20 min.This excellent performance was attributed not only to the synergistic catalytic effect of Co-Mn bimetals,but also to the hierarchical porous structure which exposes more active sites and accelerates the migration of PMS and organic pollutants.In addition,CoMn_(2)O_(4)HPNS also showed excellent reusability and high stability in multiple cycles of degradation.The active species quenching results and electron paramagnetic resonance measurements revealed that SO_(4)^(·-)greatly contributed to organic degradation,while^(1)O_(2)and·OH also involved.Moreover,a series of other transition metal oxides(Co_(3)O_(4),Fe_(2)O_(3),Mn_(3)O_(4),NiO,and CoFe_(2)O_(4))with hierarchical porous nanosheet structures were successfully fabricated with this method.This study provides a simple,general,and low-cost strategy for fabricating hierarchical porous transition metal oxides,which are promising for the environmental remediation or many other applications in the future.
基金supported by the National Natural Science Foundation of China(22072037 and 51772079)the Natural Science Foundation of Heilongjiang Province of China(LH2020B018)。
文摘Two-dimensional porous nanosheet heterostructure materials,which combine the advantages of both architecture and components,are expected to feature a significant photocatalytic performance toward CO_(2) conversion into useful fuels.Herein,we provide a facile strategy for fabricating sulfur-doped C_(3)N_(4) porous nanosheets with embedded SnO_(2)-SnS_(2) nanojunctions(S-C_(3)N_(4)/SnO_(2)-SnS_(2))via liquid impregnation-pyrolysis and subsequent sulfidation treatment using a layered supramolecular structure as the precursor of C_(3)N_(4).A hexagonal layered supramolecular structure was first prepared as the precursor of C_(3)N_(4).Then Sn^(4+) ions were intercalated into the supramolecular interlayers through the liquid impregnation method.The subsequent annealing treatment in air simultaneously realized the fabrication and efficient exfoliation of layered C_(3)N_(4) porous nanosheets.Moreover,SnO_(2) nanoparticles were formed and embedded in situ in the porous C_(3)N_(4) nanosheets.In the following sulfidation process under a nitrogen atmosphere,sulfur powder can react with SnO_(2) nanoparticles to form SnO_(2)-SnS_(2) nanojunctions.As expected,the exfoliation of sulfur-doped C_(3)N_(4) porous nanosheets and ternary heterostructure construction could be simultaneously achieved in this work.Sulfur-doped C_(3)N_(4) porous nanosheets with embedded SnO_(2)-SnS_(2) nanojunctions featured abundant active sites,enhanced visible light absorption,and efficient interfacial charge transfer.As expected,the optimized S-C_(3)N_(4)/SnO_(2)-SnS_(2) achieved a much higher gas-phase photocatalytic CO_(2) reduction performance with high yields of CO(21.68μmol g^(−1)h^(−1))and CH_(4)(22.09μmol g^(−1)h^(−1))compared with the control C_(3)N_(4),C_(3)N_(4)/SnO_(2),and S-C_(3)N_(4)/SnS_(2) photocatalysts.The selectivity of CH_(4) reached 80.30%.Such a promising synthetic strategy can be expected to inspire the design of other robust C_(3)N_(4)-based porous nanosheet heterostructures for a broad range of applications.
基金supported by the National Science Foundation of China(NSFC No.51834009 and 51801151)the Natural Science Foundation of Shaanxi Province(No.2020JZ-47 and 2020JM-451)+3 种基金the Hundred Talent Program of Shaanxi Province,the Key Laboratory Project of Shaanxi Education Department(No.18JS070,18JK0560 and 17JS081)the Shaanxi Province Science Fund for Distinguished Young Scholars(2018JC-027),China Postdoctoral Science Foundation(Grant No.2018M633643XB)the Key Research and Development Project of Shaanxi Province(No.2017ZDXM-GY033 and 2017ZDXM-GY-028)the Key Laboratory Project of Science and Technology Agency(No.13JS075).
文摘Simultaneously integrating mesocrystalline stacking superstructures,porous nanosheets and defective oxygen vacancies(OVs)into BiOCl crystals is an available strategy to enhance the visible-light-driven photocatalytic activity.Herein,we report a facile etching agent-assisted hydrothermal approach to achieve one-pot fabrication of mesocrystalline BiOCl porous nanosheet stacking superstructures with defective OVs,which show high catalytic activities towards to the visible-light-driven degradation of organic dyes.The formation of stacking superstructure in a mesocrystalline BiOCl is responsibility for increasing the transport of charge carriers.Experimental results and theoretical calculations suggest that the presence of OVs is beneficial to tuning the energy band structure for the improvement of visible light harvesting,prolonging the lifetime and enhancing the oxidation activity of photogenerated charge carriers.Additionally,the porous morphology and thin nanosheet building block could supply abundant active sites for photocatalysis.This research might arouse in-depth investigations on the development of novel precursor-modified strategy for the synthesis of high-active BiOX(X¼Cl,Br and I)-based photocatalysts.
基金financial support of the National Natural Science Foundation of China (Grant No. 21263016, 21363015, 51662029, 21863006)the Youth Science Foundation of Jiangxi Province (Grant No. 20192BAB216001)the Key Laboratory of Jiangxi Province for Environment and Energy Catalysis (20181BCD40004)。
文摘Carbon materials have shown remarkable usefulness in facilitating the performance of insulating sulfur cathode for lithium–sulfur batteries owing to their excellent conductivity and porous structure. However,the anxiety is the poor affinity toward polar polysulfides due to the intrinsic nonpolar surface of carbon.Herein, we report a direct pyrolysis of the mixture urea and boric acid to synthesize B/N–codoped hierarchically porous carbon nanosheets(B–N–CSs) as efficient sulfur host for lithium–sulfur battery. The graphene–like B–N–CSs provides high specific surface area and porous structure with abundant micropores(1.1 nm) and low–range mesopores(2.3 nm), thereby constraining the sulfur active materials within the pores. More importantly, the codoped B/N elements can further enhance the polysulfide confinement through strong Li–N and B–S interaction based on the Lewis acid–base theory. These structural superiorities significantly suppress the shuttle effect by both physical confinement and chemical interaction, and promote the redox kinetics of polysulfide conversion. When evaluated as the cathode host, the S/B–N–CSs composite displays the excellent performance with a high reversible capacity up to 772 m A h g–1 at 0.5 C and a low fading rate of ^0.09% per cycle averaged upon 500 cycles. In particular, remarkable stability with a high capacity retention of 87.1% can be realized when augmenting the sulfur loading in the cathode up to 4.6 mg cm^(-2).
基金financial support provided by the National Natural Science Foundation of China(21676078)the Natural Science Foundation of Hunan Province for Distinguished Young Scholar(2016JJ1013)+1 种基金Scientific Research Fund of Hunan Provincial Education Department(19A323)Science and Technology Planning Project of Hunan Province(2018TP1017)。
文摘Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in photo-catalysis.Nevertheless,it often suffers from moderate photo-catalytic activity due to its low specific surface area and fast recombination rate of photogenerated electrons upon photo-excitation.Herein,we overcome the bottlenecks by constructing a porous g-C_(3)N_(4) nanosheet(PCNS)through a simple thermal oxidation etching method.Benefited from its porous layer structure,the obtained PCNS exhibits large specific surface area,efficient separation of photogenerated charge carriers,as well as high exposure of active sites.As a result,it is robust and universal in visible light-driven dehydrogenation of alcohols in water under oxidant-free condition.Almost quantitative yields(>99%)of various valuable carbonyl compounds were obtained over PCNS,while bulk g-C_(3)N_(4) was far less efficient.Moreover,the photo-catalyst was highly stable and could be facilely recovered from the aqueous system for efficient reuse.The easy preparation and excellent performance made PCNS a promising and competitive photocatalyst for the solar applications.
基金supported by the PhD Start-up Fund of Science and Technology Department of Liaoning Province(No.2022-BS-306)the General Cultivation Scientific Research Project of Bohai University(No.0522xn058)the PhD Research Startup Foundation of Bohai University(No.0521bs021).
文摘The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption capability.Herein,instead of anchoring on carbon materials in single layer,MoS_(2) flower-like microspheres were stacked on the surface of pomelo peels-derived porous carbon nanosheets(C)to fabricate MoS_(2)@C nanocomposites by a facile solvothermal process.EM wave absorption performances of MoS_(2)@C nanocomposites in X-band were systematically investigated,indicating the minimum reflection loss(RLmin)of-62.3 dB(thickness of 2.88 mm)and effective absorption bandwidth(EAB)almost covering the whole X-band(thickness of 2.63 mm)with the filler loading of only 20 wt.%.Superior EM wave absorption performances of MoS_(2)@C nanocomposites could be attributed to the excellent impedance matching characteristic and dielectric loss capacity(conduction loss and polarization loss).This study revealed that the as-prepared MoS_(2)@C nanocomposites would be a novel prospective candidate for the sustainable EM absorbents with superior EM wave absorption performances.
基金supported by the National Key R&D Program of China(No.2023YFC3905804)the National Natural Science Foundation of China(Nos.22078374,22378434,22309210)+4 种基金the National Ten Thousand Talent Plan,the Key Realm Research and Development Program of Guangdong Province(No.2020B0202080001)Science and Technology Planning Project of Guangdong Province,China(No.2021B1212040008)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515011150)the Scientific and Technological Planning Project of Guangzhou(No.202206010145)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.23qnpy85).
文摘Metal-nanocluster materials have gradually become a promising electrode candidate for supercapaci-tor application.The high-efficient and rational architecture of these metal-nanocluster electrode mate-rials with satisfied supercapacitive performance are full of challenges.Herein,Fe-nanocluster anchored porous carbon(FAPC)nanosheets were constructed through a facile and low-cost impregnation-activation strategy.Various characterization methods documented that FAPC nanosheets possessed a mesopore-dominated structure with large surface area and abundant Fe-N4 active sites,which are crucial for su-percapacitive energy storage.The optimal FAPC electrode exhibited a high specific capacitance of 378 F/g at a specific current of 1 A/g and an excellent rate capability(271 F/g at 10 A/g),which are comparable or even superior to that of most reported carbon candidates.Furthermore,the FAPC-based device achieved a desired specific energy of 14.8 Wh/kg at a specific power of 700 W/kg.This work opens a new avenue to design metal-nanocluster materials for high-performance biomass waste-based supercapacitors.
基金supported by the National Key Research and Development Program of China(No.2021YFA1501003)the National Natural Science Foundation of China(Nos.92261105 and 22221003)+4 种基金the Anhui Provincial Natural Science Foundation(Nos.2108085UD06 and 2208085UD04)the Anhui Provincial Key Research and Development Project(Nos.2023z04020010 and 2022a05020053)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2021HSC-CIP002)the Joint Funds from Hefei National Synchrotron Radiation Laboratory(Nos.KY2060000180 and KY2060000195)the Yanchang foundation(No.KD2203220074).
文摘The performance of catalyst depends on the intrinsic activity of active sites and the structural characteristics of the support.Here,we simultaneously integrate single nickel(Ni)sites and platinum-nickel(PtNi)alloy nanoparticles(NPs)on a two-dimensional(2D)porous carbon nanosheet,demonstrating remarkable catalytic performance in the oxygen reduction reaction(ORR).The single Ni sites can activate the oxygen molecules into key oxygen-containing intermediate that is further efficiently transferred to the adjacent PtNi alloy NPs and rapidly reduced to H_(2)O,which establishes a relay catalysis between active sites.The porous structure on the carbon nanosheet support promotes the transfer of active intermediates between these active sites,which assists the relay catalysis by improving mass diffusion.Remarkably,the obtained catalyst demonstrates a half-wave potential of up to 0.942 V,a high mass activity of 0.54 A·mgPt^(−1),and negligible decay of activity after 30,000 cycles,which are all superior to the commercial Pt/C catalysts with comparable loading of Pt.The theoretical calculation results reveal that the obtained catalyst with defect structure of carbon support presents enhanced relay catalytic effect of PtNi alloy NPs and single Ni sites,ultimately realizing improved catalytic performance.This work provides valuable inspiration for developing low platinum loading catalyst,integrating single atoms and alloy with outstanding performance in fuel cell.
基金supported by the National Key R&D Program of China(No.2018YFB1502401)the National Natural Science Foundation of China(Nos.91961111,U20A20250,and 21901064)+3 种基金the Natural Science Foundation of Heilongjiang Province(No.ZD2021B003)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2020004)the Basic Research Fund of Heilongjiang University in Heilongjiang Province(No.2021-KYYWF-0039)Open Project of Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education.
文摘The Pt-free photocatalytic hydrogen evolution(PHE)has been the focus in the photocatalytic field.The catalytic system with the large accessible surface and good mass-transfer ability,as well as the intimate combination of co-catalyst with semiconductor is promising for the promotion of the application.Here,we have reported the design of the two-dimensional(2D)porous C_(3)N_(4)nanosheets(PCN NS)intimately combined with few-layered MoS_(2)for the high-effective Pt-free PHE.The PCN NS were synthesized based on peeling the melamine–cyanuric acid precursor(MC precursor)by the triphenylphosphine(TP)molecular followed by the calcination,mainly due to the matched size of the(100)plane distance of the precursor(0.8 nm)and the height of TP molecular.The porous structure is favorable for the mass-transfer and the 2D structure having large accessible surface,both of which are positive to promote the photocatalytic ability.The few-layered MoS_(2)are grown on PCN to give 2D MoS_(2)/PCN composites based on anchoring phosphomolybdic acid(PMo_(12))cluster on polyetherimide(PEI)-modified PCN followed by the vulcanization.The few-layered MoS_(2)have abundant edge active sites,and its intimate combination with porous PCN NS is favorable for the faster transfer and separation of the electrons.The characterization together with the advantage of 2D porous structure can largely promote the photocatalytic ability.The MoS_(2)/PCN showed good PHE activity with the high hydrogen production activity of 4,270.8μmol·h^(−1)·g^(−1)under the simulated sunlight condition(AM1.5),which was 7.9 times of the corresponding MoS_(2)/bulk C_(3)N_(4)and 12.7 times of the 1 wt.%Pt/bulk C_(3)N_(4).The study is potentially meaningful for the synthesis of PCN-based catalytic systems.
基金the National Natural Science Foundation of China(Grant Nos.22179065,22111530112)the S&T project from Shanghai Tobacco Group Co.Ltd.
文摘Owing to the complexity of electron transfer pathways,the sluggish oxygen evolution reaction process is defined as the bottleneck for the practical application of Zn-air batteries.In this effort,metal nanoparticles(Co,Ni,Fe,etc.)encapsulated within nitrogen-doped carbon materials with abundant edge sites were synthesized by one-step pyrolysis treatment using cigarette butts as raw materials,which can drastically accelerate the overall rate of oxygen evolution reaction by facilitating the adsorption of oxygenated intermediates by the edge-induced topological defects.The prepared catalyst of nitrogen-doped carbon porous nanosheets loaded with Co nanoparticles(Co@NC-500)exhibits enhanced catalytic activity toward oxygen evolution reaction,with a low overpotential of 350 mV at the current density of 10 mA·cm^(-2).Furthermore,the Zn-air battery assembled with Co@NC-500 catalyst demonstrates a desirable performance affording an open-circuit potential of 1.336 V and power density of 33.6 mW·cm^(-2),indicating considerable practical application potential.
基金The authors acknowledge the National Natural Science Foundation of China （Nos. 21576139, 21503111, 21376122, and 21273116）, Jiangsu Provincial Natural Science Foundation of Jiangsu Province （No. BK20140926）, Specialized Research Fund for the Doctoral Program of Higher Education （No. 20130202120010）, the Key Science and Technology Program of Shaanxi Province, China （No. 2014K10-06）, Fundamental Research Funds for the Central Universities （No. GK201503038）, China Scholarship Council （CSC, 201506860013）, University Postgraduate Research and Innovation Project in Jiangsu Province （No. KYZZ15_0213）, National and Local Joint Engineering Research Center of Biomedical Functional Material, and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions. The authors also thank John B. Goodenough of the university of Texas at Austin for his support and help.
文摘Catalysts for the oxygen reduction reaction （ORR） play an important role in fuel cells. Alternative non-precious metal catalysts with comparable ORR activity to Pt-based catalysts are highly desirable for the development of fuel cells. In this work, we report for the first time a spinel MnC0204/C ORR catalyst consisting of uniform MnC0204 nanoparticles cross-linked with two-dimensional （2D） porous carbon nanosheets （abbreviated as porous MnC0204/C nanosheets）, in which glucose is used as the carbon source and NaC1 as the template. The obtained porous MnCo204/C nanosheets present the combined properties of an interconnected porous architecture and a large surface area （175.3 m2-g-1）, as well as good electrical conductivity （1.15 x 102 S.cm-1）. Thus, the as-prepared MnC0204/C nanosheets efficiently facilitate electrolyte diffusion and offer an expedite transport path for reactants and electrons during the ORR. As a result, the as-prepared porous MnC0204/C nanosheet catalyst exhibits enhanced ORR activity with a higher onset potential and current density than those of its counterparts, including pure MnC0204, carbon nanosheets, and Vulcan XC-72R carbon. More importantly, the porous MnC0204/C nanosheets exhibit a com- parable electrocatalytic activity but superior stability and tolerance toward methanol crossover effects than a high-performance Pt/C catalyst in alkaline medium. The synthetic strategy outlined here can be extended to other non- precious metal catalysts for application in electrochemical energy conversion.
基金supported by the National Key Research and Development Program of China (2016YFC0204301)~~
文摘Spinel oxides containing Co and Ni are a promising substitute as a noble metal catalyst for methane combustion.Achieving a complete oxidation of methane under 400°C remains challenging,andhydrothermal 60 h NiClittle impact on activity,especially at high space velocities due to the long hydrothermal time with less absorbed oxygen species and crystal defects.Overall,these results help clarify methane activa-tion mechanisms and aid the development of more efficient low-cost catalysts.
基金support from the National Natural Science Foundation of China(Nos.21922105 and 21931001)the National Key R&D Program of China(2021YFA1501101)+4 种基金the Special Fund Project of Guiding Scientific and Technological Innovation Development of Gansu Province(No.2019ZX-04)the 111 Project(No.B20027)support by the Fundamental Research Funds for the Central Universities(Nos.lzujbky-2021-pd04,lzujbky-2021-sp41,lzujbky-2021-it12 and lzujbky-2021-37)support of the China Postdoctoral Science Foundation(No.2021M691375)the China National Postdoctoral Program for Innovative Talents(No.BX20200157)。
文摘Exploring efficient oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)electrocatalysts is crucial for developing water splitting devices.The composition and structure of catalysts are of great importance for catalytic performance.In this work,a heterogeneous Ru modified strategy is engineered to improve the catalytic performance of porous NiCo_(2)O_(4)nanosheets(NSs).Profiting from favorable elements composition and optimized structure property of decreased charge transfer barrier,more accessible active sites and increased oxygen vacancy concentration,the Ru-NiCo_(2)O_(4)NSs exhibits excellent OER activity with a low overpotential of 230 mV to reach the current density of 10 mA/cm^(2)and decent durability.Furthermore,Ru-NiCo_(2)O_(4)NSs show superior HER activity than the pristine NiCo_(2)O_(4)NSs,as well.When assembling Ru-NiCo_(2)O_(4)NSs couple as an alkaline water electrolyzer,a cell voltage of 1.60 V can deliver the current density of 10 mA/cm^(2).This work provides feasible guidance for improving the catalytic performance of spinel-based oxides.
基金National Natural Science Foundation of China,Grant/Award Numbers:51872110,21875221,22102050the special fund project of Zhengzhou basic and applied basic research,Grant/Award Numbers:ZZSZX202001,ZZSZX202002The Training Program of Youth Backbone Teacher of Henan Province of 2018,Grant/Award Number:2018GGJS178。
文摘Interfacial engineering is a powerful method to improve the bifunctional electrocatalytic performance of pure phase catalysts.While it is expected to further optimize the electronic configuration of heterojunctions to boost the reaction kinetics in hydrogen/oxygen evolution reaction(HER/OER),but remains a challenge.Herein,a novel in situ hybrid heterojunction strategy is developed to construct 2D porous Co-doped Ni/Ni_(3)N heterostructure nanosheets(Co-Ni/Ni_(3)N)by pyrolysis of partially cobalt substituted nickel-zeolitic imidazolate framework(CoNi-ZIF)nanosheets under NH3 atmosphere.A combined experimental and theoretical studies manifest that the hybrid heterostructures can display regulative electronic states and downshift d-band center from the Fermi level,as well as optimize the adsorption energy of reaction intermediates,thus reducing the thermodynamic energy barriers and accelerating the catalytic kinetics.Consequently,benefitting from the optimized electronic configuration,hierarchical hollow nanosheets architecture,and abundant doped heterojunctions,the hybrid Co-Ni/Ni_(3)N heterostructure catalyst exhibits efficient catalytic activity for both HER(60 mV)and OER(322 mV)at 10 mA cm^(-2)in alkaline media,which is 105 and 47 mV lower than that of pure Ni_(3)N,respectively.The electrochemically active surface area of Co-Ni/Ni_(3)N is two times higher than that of Ni3N.Furthermore,the coupled practical water electrolyzer requires a low voltage of 1.575 V to reach 10 mA cm^(-2),and it can be driven by a 1.5 V battery.This work highlights the interface engineering guidance for the rational establishment of hybrid interfaces by electronic modulation of interfacial effect for alkaline water splitting.
基金financial support from the National Natural Science Foundation of China(Nos.21101176 and 21676036)the Fundamental Research Funds for the Central Universities of Chongqing University(Nos.2018CDQYCH0028,2018CDXYHG0028 and 2019CDXYHG0013)+1 种基金the Graduate Research and Innovation Foundation of Chongqing(No.CYS-20040)the Large-scale Equipment Sharing Fund of Chongqing University(Nos.201903150149 and 202003150020)。
文摘Unique two-dimensional(2D)porous nanosheets with overwhelmingly rich channels and large specific surface area exhibit superior electrochemical capacitance performance,as compared to the conventional zero-and one-dimensional counterparts.As ternary transition metal sulfides(TMSs)are well recognized for their high electrochemical activity and capacity,and the replacement of oxygen with sulfur may result in high stability and flexible properties of the nanomaterials,as compared to transition metal oxides,herein we report the synthesis of 2D porous nanosheet arrays of Zn_(x)Co_(1-x)S(x=0,0.25,0.5,0.75,and 1)via a facile hydrothermal process.Due to the synergistic effect of the metal components and a unique 2D porous structure,the Zn_(0.5)Co_(0.5)S electrode was found to stand out as the best among the series,with a high specific capacity of 614 C g^(-1)at 1 A g^(-1)and excellent cycle retention rate of 90%over 10,000 cycles at 10 A g^(-1).Notably,a supercapattery based on a Zn_(0.5)Co_(0.5)S positive electrode and an activated carbon(AC)negative electrode(Zn_(0.5)Co_(0.5)S//AC)was found to display a 1.6 V voltage window,a 61 mA h g^(-1)specific capacity at 1 A g^(-1),a 49 Wh kg^(-1)energy density at 957 W kg^(-1)power density,and excellent cycling performance(88%over 10,000 cycles),suggesting tremendous potential of Zn_(0.5)Co_(0.5)S in the development of high-performance supercapattery devices.
基金This work was supported by the NSFC(21501096,22075223)Natural Science Foundation of Jiangsu(BK20150086,BK20201120)+1 种基金the Foundation of the Jiangsu Education Committee(15KJB150020)the Six Talent Peaks Project in Jiangsu Province(JY-087)and the Innovation Project of Jiangsu Province.
文摘Although molybdenum disulfide (MoS_(2))-based materials are generally known as active electrocatalysts for the hydrogen evolution reaction (HER), the inert performance for the oxygen evolution reaction (OER) seriously limits their wide applications in alkaline electrolyzers due to there exists too strong metal-sulfur (M−S) bond in MoS_(2). Herein, by means of surface reorganization engineering of bimetal Al, Co-doped MoS_(2) (devoted as AlCo_(3)-MoS_(2)) through in situ substituting partial oxidation, we successfully significantly activate the OER activity of MoS_(2), which affords a considerably low overpotential of 323 mV at −30 mA cm^(−2), far lower than those of MoS_(2), Al-MoS_(2) and Co-MoS_(2) catalysts. Essentially, the AlCo_(3)-MoS_(2) substrate produces lots of M−O (M=Al, Co and Mo) species with oxygen vacancies, which trigger the surface self-reconstruction of pre-catalysts and simultaneously boost the electrocatalytic OER activity. Moreover, benefiting from the moderate M−O species formed on the surface, the redistribution of surface electron states is induced, thus optimizing the adsorption of OH* and OOH* intermediates on metal oxyhydroxides and awakening the OER activity of MoS_(2).
基金the National Key R&D Program of China(2016YFA0202602)the National Natural Science Foundation of China(U1663225)+3 种基金the Fundamental Research Funds for the Central Universities(2020-YB-009)the Academy of Scientific Research and Technology(6611,ASRT,Egypt)the 111 National project(B20002)from the Ministry of Science and Technology and the Ministry of Education,ChinaSinopec Ministry of Science and Technology Basic Prospective Research Project(217027-5 and 218025-9)。
文摘Lithium-sulfur(Li-S)batteries have attracted significant attention for their high specific capacity,non-toxic and harmless advantages.However,the shuttle effect limits their development.In this work,small-sized tin disulfide(SnS_(2))nanoparticles are embedded between interlayers of twodimensional porous carbon nanosheets(PCNs),forming a multi-functional nanocomposite(PCN-SnS_(2))as a cathode carrier for Li-S batteries.The graphitized carbon nanosheets improve the overall conductivity of the electrode,and the abundant pores not only facilitate ion transfer and electrolyte permeation,but also buffer the volume change during the charge and discharge process to ensure the integrity of the electrode material.More importantly,the physical confinement of PCN,as well as the strong chemical adsorption and catalytic reaction of small SnS_(2)nanoparticles,synergistically reduce the shuttle effect of polysulfides.The interaction between a porous layered structure and physical-chemical confinement gives the PCN-SnS_(2)-S electrode high electrochemical performance.Even at a high rate of 2 C,a discharge capacity of 650 mA h g^(-1)is maintained after 150 cycles,underscoring the positive results of SnS_(2)-based materials for Li-S batteries.The galvanostatic intermittent titration technique results further confirm that the PCN-SnS_(2)-S electrode has a high Li+transmission rate,which reduces the activation barrier and improves the electrochemical reaction kinetics.This work provides strong evidence that reducing the size of SnS_(2)nanostructures is beneficial for capturing and reacting with polysulfides to alleviate their shuttle effect in Li-S batteries.
基金supported by the Major special projects of Science and Technology Department of Sichuan Province(No.2020ZDZX0020)the Key R&D projects of Sichuan Science and Technology Department(No.2019YFG0056)。
文摘Recently,metal-based carbon materials have been verified to be an effective persulfate activator,but secondary pollution caused by metal leaching is inevitable.Hence,a green metalfree 3D macroscopic N-doped porous carbon nanosheets(NPCN)was synthesized successfully.The obtained NPCN showed high adsorption capacity of tetracycline(TC)and excellent persulfate(PS)activation ability,especially when calcined at 700℃(NPCN-700).The maximum adsorption capacity of NPCN-700 was 121.51 mg/g by H-bonds interactions.Moreover,the adsorption process followed pseudo-second-order kinetics model and Langmuir adsorption isotherm.The large specific surface area(365.27 mg/g)and hierarchical porous structure of NPCN-700 reduced the mass transfer resistance and increased the adsorption capacity.About 96.39%of TC was removed after adding PS.The effective adsorption of the catalyst greatly shortened the time for the target organic molecules to migrate to the catalyst.Moreover,the NPCN-700 demonstrated high reusability with the TC removal rate of 80.23%after 4 cycles.Quenching experiment and electron paramagnetic resonance(EPR)test confirmed the non-radical mechanism dominated by ^(1)O_(2).More importantly,the C=O groups,defects and Graphitic N acted as active sites to generate ^(1)O_(2).Correspondingly,electrochemical measurement revealed the direct electron transfer pathway of TC degradation.Finally,multiple degradation intermediates were recognized by the LC-MS measurement and three possible degradation pathways were proposed.Overall,the prepared NPCN had excellent application prospects for removal of antibiotics due to its remarkable adsorption and catalytic degradation capabilities.
基金The authors acknowledge the financial support by the National Natural Science Foundation of China(Nos.21922501,21625102,and 21471018)the China National Petroleum Corporation Research Fund Program,and the Research Institute of Petroleum Exploration and Development Research Fund Program.
文摘Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.However,the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading.In this work,a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoS_(x)material(CNS@MoS_(x)).This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3%and~100%Coulombic efficiency after 400 cycles at 1.2 A·g^(-1),much superior compared to bare MoS_(2).Density functional theory(DFT)calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoS_(x)are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoS_(x)via strong chemical bonding,enabling MoS_(x)to be firmly confined on the substrate.Moreover,this unique hierarchical complex structure ensures the fast migration of Zn^(2+)within MoS_(x)interlayer.
基金financially supported by the National Natural Science Foundation of China (22209039)Top-notch Personnel Fund of Henan Agricultural University (30500682)。
文摘Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts the C–C bond cleavage.Inspired by the molecular orbital theory,we proposed the d-state-editing strategy to construct more unoccupied d-states of Pd for the enhanced interaction with CH_(3)CO^(*) to break C–C bonds.As expected,the reduced number of e_g electrons and more unoccupied d-states of Pd successfully formed on as-prepared porous Rh Au–Pd Cu nanosheets(PNSs).Theoretical calculations show that the optimized d-states of Rh Au–Pd Cu PNS can effectively improve the adsorption of CH_(3)CO^(*) and drastically reduce the energy barrier of C–C bond cleavage,thus boosting the complete oxidation of ethanol.The charge ratio of C_1 pathway on Rh Au–Pd Cu PNSs is 51.5%,more than 2 times higher than that of Pd NSs.Our finding provides an innovative perspective for the design of highly-efficient noble-based electrocatalysts.
