The key to construct high-energy supercapacitors is to maximize the capacitance of electrode and the voltage of the device. Realizing this purpose by utilizing sustainable and low-cost resources is still a big challen...The key to construct high-energy supercapacitors is to maximize the capacitance of electrode and the voltage of the device. Realizing this purpose by utilizing sustainable and low-cost resources is still a big challenge. Herein, N, B co-doped carbon nanosheets are obtained through the proposed dual-template assisted approach by using methyl cellulose as the precursor. Due to the synergistic effects form the high surface area with the hierarchical porous structure, N/B dual doping, and a high degree of graphitization, the resultant carbon electrode exhibits a high capacitance of 572 F g^(-1)at 0.5 A g^(-1)and retains 281 F g^(-1)at 50 A g^(-1)in an acidic electrolyte. Furthermore, the symmetric device assembled using bacterial cellulose-based gel polymer electrolyte can deliver high energy density of 43 W h kg^(-1)and excellent cyclability with 97.8% capacity retention after 20 000 cycles in “water in salt” electrolyte. This work successfully realizes the fabrication of high-performance allcellulose-based quasi-solid-state supercapacitors, which brings a cost-effective insight into jointly designing electrodes and electrolytes for supporting highly efficient energy storage.展开更多
From the perspective of electronic structure modulation,it is highly desirable to rationally design the active urea oxidation reaction(UOR)catalysts through interface engineering.The binary cooperative heterostructure...From the perspective of electronic structure modulation,it is highly desirable to rationally design the active urea oxidation reaction(UOR)catalysts through interface engineering.The binary cooperative heterostructure systems have been shown significant enhancement for catalyzing UOR,but their performance still remains unsatisfactory for industrialization because of the unfavorable intermediate adsorption/desorption and deficient electron transfer channels.In response,taking the ternary cooperative Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure as the proof-of-concept paradigm,a catalytic model is rationally put forward to elucidate the UOR promotion mechanism at the molecular level.The rod-like Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) nanoarrays with three-phase heterojunction are experimentally fabricated on Ni foam(named as Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF)via simple two-step processes.The density functional theory calculations disclose that construction of Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure model not only induce charge redistribution at the interfacial region for creating innumerable electron transfer channels,but also endow it with a moderate d-band center that could help to build a balance between adsorption and desorption of diverse UOR intermediates.Benefiting from the unique rod-like nanoarrays with large specific surface area and the optimized electronic structure,the well-designed Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF could act as a robust catalyst for driving UOR at industrial-level current densities under tough environments,offering great potential for commercial applications.展开更多
Carbonaceous material with favorable K^(+)intercalation feature is considered as a compelling anode for potassium-ion batteries(PIBs).However,the inferior rate performance and cycling stability impede their large-scal...Carbonaceous material with favorable K^(+)intercalation feature is considered as a compelling anode for potassium-ion batteries(PIBs).However,the inferior rate performance and cycling stability impede their large-scale application.Here,a facile template method is utilized to synthesize boron doping carbon nanobubbles(BCNBs).The incorporation of boron into the carbon structure introduces abundant defective sites and improves conductivity,facilitating both the intercalation-controlled and capacitivecontrolled capacities.Moreover,theoretical calculation proves that boron doping can effectively improve the conductivity and facilitate electrochemical reversibility in PIBs.Correspondingly,the designed BCNBs anode delivers a high specific capacity(464 mAh g^(-1)at 0.05 A g^(-1))with an extraordinary rate performance(85.7 mAh g^(-1)at 50 A g^(-1)),and retains a considerable capacity retention(95.2%relative to the 100th charge after 2000 cycles).Besides,the strategy of pre-forming stable artificial inorganic solid electrolyte interface effectively realizes high initial coulombic efficiency of 79.0%for BCNBs.Impressively,a dual-carbon potassium-ion capacitor coupling BCNBs anode displays a high energy density(177.8 Wh kg^(-1)).This work not only shows great potential for utilizing heteroatom-doping strategy to boost the potassium ion storage but also paves the way for designing high-energy/power storage devices.展开更多
It is significant for the rational construction of the high–efficient bifunctional electrocatalysts for in–depth understandings of how to improve the electron transfer and ion/oxygen transport in catalyzing oxygen r...It is significant for the rational construction of the high–efficient bifunctional electrocatalysts for in–depth understandings of how to improve the electron transfer and ion/oxygen transport in catalyzing oxygen reduction reaction and oxygen evolution reaction(ORR and OER),but still full of vital challenges.Herein,we synthesize the novel“three–in–one”catalyst that engineers core–shell Mott–Schottky Co_(9)S_(8)/Co heterostructure on the defective reduced graphene oxide(Co_(9)S_(8)/Co–rGO).The Co_(9)S_(8)/Co–rGO catalyst exhibits abundant Mott–Schottky heterogeneous–interfaces,the well–defined core–shell nanostructure as well as the defective carbon architecture,which provide the multiple guarantees for enhancing the electron transfer and ion/oxygen transport,thus boosting the catalytic ORR and OER activities in neutral electrolyte.As expected,the integrated core–shell Mott–Schottky Co_(9)S_(8)/Co–rGO catalyst delivers the most robust and efficient rechargeable ZABs performance in neutral solution electrolytes accompanied with a power density of 59.5 mW cm^(-2) and superior cycling stability at 5 mA cm^(-2) over 200 h.This work not only emphasizes the rational designing of the high–efficient bifunctional oxygen catalysts from the fundamental understanding of accelerating the electron transfer and ion/oxygen transport,but also sheds light on the practical application prospects in more friendly environmentally neutral rechargeable ZABs.展开更多
We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,...We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,2,5,and 10 A g−1,the SNCC shows reversible capacities of 369,328,249,208,150,and 121 mA h g−1,respectively.Due to a high packing density of 1.01 g cm^(−3),the volumetric capacities are also uniquely favorable,being 373,331,251,210,151,and 122 mA h cm^(−3)at these currents,respectively.SNCC also shows promising initial Coulombic efficiency of 69.0%and extended cycling stability with 99.8%capacity retention after 1000 cycles.As proof of principle,an SNCC-based PIC is fabricated and tested,achieving 94.3Wh kg^(−1)at 237.5Wkg^(−1)and sustaining over 6000 cycles at 30 A g−1 with 84.5%retention.The internal structure of S and N codoped SNCC is based on highly dilated and defective graphene sheets arranged into nanometer-scale walls.Using a baseline S-free carbon for comparison(termed NCC),the role of S doping and the resultant dilated structure was elucidated.According to galvanostatic intermittent titration technique and electrochemical impedance spectroscopy analyses,as well as COMSOL simulations,this structure promotes rapid solid-state diffusion of potassium ions and a solid electrolyte interphase that is stable during cycling.X-ray diffraction was used to probe the ion storage mechanisms in SNCC,establishing the role of reversible potassium intercalation and the presence of KC36,KC24,and KC8 phases at low voltages.展开更多
First-row(3 d)transition metal oxyhydroxides have attracted increasing attention due to their various advantages.Although investigating the oxidation mechanism and processing such materials into hierarchical architect...First-row(3 d)transition metal oxyhydroxides have attracted increasing attention due to their various advantages.Although investigating the oxidation mechanism and processing such materials into hierarchical architectures are greatly desired for their further development,it remains unclear how the oxidation state change occurs,and efforts to produce hierarchical oxyhydroxides in compliance with high ecological and economic standards have progressed slowly.Here,we describe a facile one-step coprecipitation route for the preparation of hierarchical CoOOH,NiOOH and MnOOH,which involves the diffusion of NH_(3)originating from ammonium hydroxide solution into an aqueous solution containing metal ion salts and K_(2)S_(2)O_(8).Comprehensive characterizations by scanning electron microscope,transmission electron microscopy,X-ray diffraction analysis,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy and in situ p H measurement demonstrated that K_(2)S_(2)O_(8)induces the oxidation state change of metal ion species after the start of hydrolysis.Meanwhile,it was found that,benefiting from the OH–concentration gradient created by the NH_(3)diffusion method and the suitable growth environment provided by the presence of K_(2)S_(2)O_(8)(high nucleation rate and secondary nucleation),the formation of hierarchical oxyhydroxide structures can be realized in aqueous solution at ambient temperature without the use of heat energy and additional structure-directing agents.The hierarchical CoOOH structures are performed as the electrocatalysts for the oxygen evolution reaction in alkaline media,which exhibit good activity with an overpotential of 320 m V at 10 m A cm^(-2)and a low Tafel slope of 59.6 m V dec^(–1),outperforming many congeneric electrocatalysts.Overall,our study not only provides important insights to understand the formation mechanism of hierarchical oxyhydroxides,but also opens up new opportunities for the preparation of hierarchical oxyhydroxides via a facile,green and low-cost method.展开更多
Cathode interfacial materials(CIMs)stand as critical elemental in organic solar cells(OSCs),which can align energy levels,and foster ohmic contacts between the cathode and active layer of the OSCs.Nevertheless,the lag...Cathode interfacial materials(CIMs)stand as critical elemental in organic solar cells(OSCs),which can align energy levels,and foster ohmic contacts between the cathode and active layer of the OSCs.Nevertheless,the lagging advancement in CIMs has concurrently engendered the oversight of theoretical inquiries pertaining to the impact of molecular structure on their performance.Delving into this realm,we present two propeller-shaped isomers,4,4',4''-(benzo[1,2-b:3,4-b':5,6-b'']trithiophene-2,5,8-triyl)tris(2-(3-(dimethylamino)propyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione)(3ONIN)and 6,6',6''-(benzo[1,2-b:3,4-b':5,6-b'']trithiophene-2,5,8-triyl)tris(2-(3-(dimethylamino)propyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione)(3PNIN),distinguished by their molecular planarity,as a promising foundation for crafting highly efficient OSCs.This study illuminates the superiority of 3PNIN with more plane structure,exemplified by its enhanced molar extinction coefficient,deeper lowest unoccupied molecular orbital(LUMO)and highest occupied molecular orbital(HOMO)energy levels,intensified self-doping effect,heightened electron mobility,and elevated conductivity,in comparison to its counterpart,3ONIN.As a result,3PNIN and 3ONIN-treated OSC devices yield efficiencies of 17.73%and 16.82%,respectively.This finding serves as a compelling validation of the critical role played by molecular planarity in influencing CIM performance.展开更多
Oxygen reduction reaction(ORR)plays an important role in the next-generation energy storage technologies,whereas it involves the sluggish and complicated proton-coupled electron transfer(PCET)steps that greatly limit ...Oxygen reduction reaction(ORR)plays an important role in the next-generation energy storage technologies,whereas it involves the sluggish and complicated proton-coupled electron transfer(PCET)steps that greatly limit the ORR kinetics.Therefore,it is urgent to construct an efficient catalyst that could simultaneously achieve the rapid oxygen-containing intermediates conversion and fast PCET process but remain challenging.Herein,the adjacent Fe_(3)C nanoparticles coupling with single Fe sites on the bubble-wrap-like porous N-doped carbon(Fe_(3)C@FeSA-NC)were deliberately constructed.Theoretical investigations reveal that the adjacent Fe_(3)C nanoparticles speed up the water dissociation and serve as proton-feeding centers for boosting the ORR kinetics of single Fe sites.Benefiting from the synergistic effect of the Fe_(3)C and single Fe sites,the Fe_(3)C@FeSA-NC affords an excellent half-wave potential of 0.88 V,and enables the assembled Zn-air batteries with the high peak power density of 164.5 mW·cm^(-2)and long-term stability of over 200 h at high current densities at 50 mA·cm^(-2).This work clarifies the mechanism for improving ORR kinetics of single atomic sites by engineering the adjacent proton-feeding centers,shedding light on the rational design of cost-effective electrocatalysts for energy conversion and storage technologies.展开更多
Nanoscale thin-film composite(TFC)polyamide membranes are highly desirable for desalination owing to their excellent separation performance.It is a permanent pursuit to further improve the water flux of membrane witho...Nanoscale thin-film composite(TFC)polyamide membranes are highly desirable for desalination owing to their excellent separation performance.It is a permanent pursuit to further improve the water flux of membrane without deteriorating the salt rejection.Herein,we fabricated a high-performance polyamide membrane with nanoscale structures through introducing multifunctional crown ether interlayer on the porous substrate impregnated with m-phenylenediamine.The crown ether interlayer can reduce the diffusion of amine monomers to reaction interface influenced by its interaction with m-phenylenediamine and the spatial shielding effect,leading to a controlled interfacial polymerization(IP)reaction.Besides,crown ether with intrinsic cavity is also favorable to adjust the IP process and the microstructure of polyamide layer.Since the outer surface of the nanocavity is lipophilic,crown ether has good solvency with the organic phase,thus attracting more trimesoyl chloride molecules to the interlayer and promoting the IP reaction in the confined space.As a result,a nanoscale polyamide membrane with an ultrathin selective layer of around 50 nm is obtained.The optimal TFC polyamide membrane at crown ether concentration of 0.25 wt.%exhibits a water flux of 61.2 L·m^(−2)·h^(−1),which is 364%of the pristine TFC membrane,while maintaining a rejection of above 97%to NaCl.The development of the tailor-made nanoscale polyamide membrane via constructing multifunctional crown ether interlayer provides a straightforward route to fabricate competitive membranes for highly efficient desalination.展开更多
Deliberate modulation of the electronic structure via interface engineering is one of promising perspectives to build advanced catalysts for urea oxidation reaction(UOR)at high current densities.However,it still remai...Deliberate modulation of the electronic structure via interface engineering is one of promising perspectives to build advanced catalysts for urea oxidation reaction(UOR)at high current densities.However,it still remains some challenges originating from the intrinsically sluggish UOR dynamics and the high energy barrier for urea adsorption.In response,we report the coupled NiSe_(2)nanowrinkles with Ni_(5)P_(4)nanorods heterogeneous structure onto Ni foam(denoted as NiSe_(2)@Ni_(5)P_(4)/NF)through successive phosphorization and selenization strategy,in which the produced closely contacted interface could provide high-flux electron transfer pathways.Theoretical findings decipher that the fast charge transfer takes place at the interfacial region from Ni_(5)P_(4)to NiSe_(2),which is conducive to optimizing adsorption energy of urea molecules.As expected,the well-designed NiSe_(2)@Ni_(5)P_(4)/NF only requires the low potential of 1.402 V at the current density of 500 mA·cm^(-2).More importantly,a small Tafel slope of 27.6 mV·dec^(-1),a high turnover frequency(TOF)value of 1.037 s^(-1)as well as the prolonged stability of 950 h at the current density of 100 mA·cm^(-2)are also achieved.This study enriches the understanding on the electronic structure modulation via interface engineering and offers bright prospect to design advanced UOR catalysts.展开更多
Single-atom catalysts(SACs)have received considerable attention in hydrogenation of nitroaromatic compounds to aromatic amines.In order to enhance the exposure of single atoms and overcome the mass transfer limitation...Single-atom catalysts(SACs)have received considerable attention in hydrogenation of nitroaromatic compounds to aromatic amines.In order to enhance the exposure of single atoms and overcome the mass transfer limitation,construction of hierarchical porous supports for single atoms is highly desirable.Herein,we report a straightforward method to synthesize Co single-atoms supported on a hollow-on-hollow structured carbon monolith(Co_(1)/HOHC-M)by pyrolysis ofα-cellulose monolith loaded with PS-core@ZnCo-zeolite imidazolate frameworks-shell nanospheres(PS@Zn-ZIFs/α-cellulose).The hollow-on-hollow structure consists of a large hollow void with a diameter of~290 nm(derived from the decomposition of polystyrene(PS)nanospheres)and a thin shell with hollow spherical pores with a diameter of~10 nm(derived from the evaporation of ZnO nanoparticles that are in-situ formed during pyrolysis in the presence of CO_(2)fromα-cellulose decomposition).Benefitting from the hierarchically porous architecture,the Co_(1)/HOHC-M exhibits excellent catalytic performance(reaction rate of 421.6 mmol·gCo^(-1)·h^(−1))in the transfer hydrogenation of nitrobenzene to aniline,outperforming the powdered sample of Co_(1)/HCS without the hollow spherical mesopores(reaction rate of 353.8 mmol·gCo^(-1)·h^(−1)).It is expected that this strategy could be well extended in heterogeneous catalysis,given the wide applications of porous carbon-supported single-atom catalysts.展开更多
Electrochemistry for energy conversion and catalysis has received unprecedented attention in sustainable society development due to its significant role in renewable energy system construction,which includes the funda...Electrochemistry for energy conversion and catalysis has received unprecedented attention in sustainable society development due to its significant role in renewable energy system construction,which includes the fundamental energy technology of fuel cells and electrical storage devices.To drive a specific electrochemical reaction,highly efficient electrode materials are required which can accelerate the reactions by kinetic improvement or intrinsic activity boosting.It is well known that the"Structure Determines Properties"in chemistry,and to obtain high performance for an electrochemical reaction in energy conversion and catalysis,electrode materials with optimal structure should be probed,and the structure-property correlation should be revealed.All these concerns are very important for electrode materials development.展开更多
OBJECTIVE:A systematic review of the literature was conducted to evaluate the curative effect and safety of Duhuojisheng Tang on prolapse of the lumbar intervertebral disc.METHODS:The databases of PubMed,China Nationa...OBJECTIVE:A systematic review of the literature was conducted to evaluate the curative effect and safety of Duhuojisheng Tang on prolapse of the lumbar intervertebral disc.METHODS:The databases of PubMed,China National Knowledge Infrastructure(CNKI),Chinese Scientific Journals Database(VIP),Chinese Biomedical Literature Database(CBM) and Chinese Medical Citation Index(CMCI) were searched up to January 30,2012.Randomized controlled trials were selected to compare Duhuojisheng Tang with one or more of the following treatments:traction,acupuncture,massage,cupping and Western medical treatment.The quality-evaluating standard and the software RevMan 5.1 in Cochrane coordinative net were used to analyze the data.The effective indexes of the results were clinical curative rate,effectiveness of alleviating clinical symptoms and adverse reaction.RESULTS:Thirty-one randomized controlled trials of low quality,involving 3915 patients were systematically evaluated.Statistical analyses showed that good curative effect was achieved in both the group using Duhuojisheng Tang alone and with combined therapies.CONCLUSION:Using Duhuojisheng Tang alone or combined with other therapies can effectively improve pain,leg-raising height and other clinical symptoms of patients with prolapse of lumbar intervertebral disc.Due to low methodological quality of the articles,no exact recommendations can be made.展开更多
Developing highly efficient,easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel.In response,the coupled hierarchical...Developing highly efficient,easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel.In response,the coupled hierarchical Ni/Fe-based MOF nanosheet arrays with embedded metal sulfide nanoclusters onto nickel foam skeleton(denoted as Fe-Ni_(3)S_(2)@NiFe-MOF/NF)are fabricated,in which the Fe-Ni_(3)S_(2) clusters could effectively restrain the aggregation of the layer metal-organic frameworks(MOF)nanosheets and adjust the local electronic structures of MOFs nanosheets.Benefiting from the rapid charge transfer and the exposure of abundant active sites,the well-designed Fe-Ni_(3)S_(2)@NiFe-MOF/NF displays excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performance.More importantly,when equipped in the alkaline water electrolyzer,the Fe-Ni_(3)S_(2)@Ni Fe-MOF/NF enables the system with a mere 1.6 V for achieving the current density of 10 mA cm^(-2).This work offers a paradigm for designing efficient bifunctional HER/OER electrocatalysts based on the hybrid materials of nanostructured metal sulfide and MOF.展开更多
Interface engineering has gradually attracted substantial research interest in constructing active bifunctional catalysts toward urea electrolysis.The fundamental understanding of the crystallinity transition of the c...Interface engineering has gradually attracted substantial research interest in constructing active bifunctional catalysts toward urea electrolysis.The fundamental understanding of the crystallinity transition of the components on both sides of the interface is extremely significant for realizing controllable construction of catalysts through interface engineering,but it still remains a challenge.Herein,the Ni/NiO heterogenous nanoparticles are successfully fabricated on the porous N-doped carbon spheres by a facile hydrothermal and subsequent pyrolysis strategy.And for the first time we show the experimental observation that the Ni/NiO interface can be fine-tuned via simply tailoring the heating rate during pyrolysis process,in which the crystalline/amorphous or crystalline/crystalline Ni/NiO heterostructure is deliberately constructed on the porous N-doped carbon spheres(named as CA-Ni/NiO@NCS or CC-Ni/NiO@NCS,respectively).By taking advantage of the unique porous architecture and the synergistic effect between crystalline Ni and amorphous NiO,the well-designed CA-Ni/NiO@NCS displays more remarkable urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity than its crystalline/crystalline counterpart of CC-Ni/NiO@NCS.Particularly,the whole assembled two-electrode electrolytic cell using the elaborate CANi/NiO@NCS both as the anode and cathode can realize the current density of 10 mA·cm^(−2)at a super low voltage of 1.475 V(264 mV less than that of pure water electrolysis),as well as remarkable prolonged stability over 63 h.Besides,the H_(2)evolution driven by an AA battery and a commercial solar cell is also studied to enlighten practical applications for the future.展开更多
Employing the alkaline water electrolysis system to generate hydrogen holds great prospects but still poses significant challenges,particularly for the construction of hydrogen evolution reaction(HER)catalysts operati...Employing the alkaline water electrolysis system to generate hydrogen holds great prospects but still poses significant challenges,particularly for the construction of hydrogen evolution reaction(HER)catalysts operating at ampere-level current density.Herein,the unique Ru and RuP_(2)dual nano-islands are deliberately implanted on N-doped carbon substrate(denoted as Ru-RuP_(2)/NC),in which a built-in electric field(BEF)is spontaneously generated between Ru-RuP_(2)dual nano-islands driven by their work function difference.Experimental and theoretical results unveil that such constructed BEF could serve as the driving force for triggering fast hydrogen spillover process on bridged Ru-RuP_(2)dual nano-islands,which could invalidate the inhibitory effect of high hydrogen coverage at ampere-level current density,and synchronously speed up the water dissociation on Ru nano-islands and hydrogen adsorption/desorption on RuP_(2)nano-islands through hydrogen spillover process.As a result,the Ru-RuP_(2)/NC affords an ultra-low overpotential of 218 mV to achieve 1.0 A·cm^(−2)along with the superior stability over 1000 h,holding the great promising prospect in practical applications at ampere-level current density.More importantly,this work is the first to advance the scientific understanding of the relationship between the constructed BEF and hydrogen spillover process,which could be enlightening for the rational design of the cost-effective alkaline HER catalysts at ampere-level current density.展开更多
基金supported by the National Natural Science Foundation of China (No.22179123 and 21471139)the Shandong Provincial Natural Science Foundation,China (ZR2020ME038)+2 种基金the Fundamental Research Funds for the Central Universities (No.201941010)the Shandong Provincial Key R&D Plan and the Public Welfare Special Program,China (2019GGX102038)the Qingdao City Programs for Science and Technology Plan Projects (19-6-2-77-cg)。
文摘The key to construct high-energy supercapacitors is to maximize the capacitance of electrode and the voltage of the device. Realizing this purpose by utilizing sustainable and low-cost resources is still a big challenge. Herein, N, B co-doped carbon nanosheets are obtained through the proposed dual-template assisted approach by using methyl cellulose as the precursor. Due to the synergistic effects form the high surface area with the hierarchical porous structure, N/B dual doping, and a high degree of graphitization, the resultant carbon electrode exhibits a high capacitance of 572 F g^(-1)at 0.5 A g^(-1)and retains 281 F g^(-1)at 50 A g^(-1)in an acidic electrolyte. Furthermore, the symmetric device assembled using bacterial cellulose-based gel polymer electrolyte can deliver high energy density of 43 W h kg^(-1)and excellent cyclability with 97.8% capacity retention after 20 000 cycles in “water in salt” electrolyte. This work successfully realizes the fabrication of high-performance allcellulose-based quasi-solid-state supercapacitors, which brings a cost-effective insight into jointly designing electrodes and electrolytes for supporting highly efficient energy storage.
基金funding and supporting this work through Research Partnership Program(No.RP-21-09-75)。
文摘From the perspective of electronic structure modulation,it is highly desirable to rationally design the active urea oxidation reaction(UOR)catalysts through interface engineering.The binary cooperative heterostructure systems have been shown significant enhancement for catalyzing UOR,but their performance still remains unsatisfactory for industrialization because of the unfavorable intermediate adsorption/desorption and deficient electron transfer channels.In response,taking the ternary cooperative Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure as the proof-of-concept paradigm,a catalytic model is rationally put forward to elucidate the UOR promotion mechanism at the molecular level.The rod-like Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) nanoarrays with three-phase heterojunction are experimentally fabricated on Ni foam(named as Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF)via simple two-step processes.The density functional theory calculations disclose that construction of Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure model not only induce charge redistribution at the interfacial region for creating innumerable electron transfer channels,but also endow it with a moderate d-band center that could help to build a balance between adsorption and desorption of diverse UOR intermediates.Benefiting from the unique rod-like nanoarrays with large specific surface area and the optimized electronic structure,the well-designed Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF could act as a robust catalyst for driving UOR at industrial-level current densities under tough environments,offering great potential for commercial applications.
基金supported by the National Natural Science Foundation of China(No.22179123 and 21471139)the Shandong Provincial Natural Science Foundation,China(ZR2020ME038)the Fundamental Research Funds for the Central Universities(No.202262010 and 201941010)
文摘Carbonaceous material with favorable K^(+)intercalation feature is considered as a compelling anode for potassium-ion batteries(PIBs).However,the inferior rate performance and cycling stability impede their large-scale application.Here,a facile template method is utilized to synthesize boron doping carbon nanobubbles(BCNBs).The incorporation of boron into the carbon structure introduces abundant defective sites and improves conductivity,facilitating both the intercalation-controlled and capacitivecontrolled capacities.Moreover,theoretical calculation proves that boron doping can effectively improve the conductivity and facilitate electrochemical reversibility in PIBs.Correspondingly,the designed BCNBs anode delivers a high specific capacity(464 mAh g^(-1)at 0.05 A g^(-1))with an extraordinary rate performance(85.7 mAh g^(-1)at 50 A g^(-1)),and retains a considerable capacity retention(95.2%relative to the 100th charge after 2000 cycles).Besides,the strategy of pre-forming stable artificial inorganic solid electrolyte interface effectively realizes high initial coulombic efficiency of 79.0%for BCNBs.Impressively,a dual-carbon potassium-ion capacitor coupling BCNBs anode displays a high energy density(177.8 Wh kg^(-1)).This work not only shows great potential for utilizing heteroatom-doping strategy to boost the potassium ion storage but also paves the way for designing high-energy/power storage devices.
基金financially supported by the National Natural Science Foundation of China (21775142)the Sino–German Center for Research Promotion (Grants GZ 1351)+1 种基金the Natural Science Foundation of Shandong Province (ZR2020ZD10)the Research Funds for the Central Universities (202061031)。
文摘It is significant for the rational construction of the high–efficient bifunctional electrocatalysts for in–depth understandings of how to improve the electron transfer and ion/oxygen transport in catalyzing oxygen reduction reaction and oxygen evolution reaction(ORR and OER),but still full of vital challenges.Herein,we synthesize the novel“three–in–one”catalyst that engineers core–shell Mott–Schottky Co_(9)S_(8)/Co heterostructure on the defective reduced graphene oxide(Co_(9)S_(8)/Co–rGO).The Co_(9)S_(8)/Co–rGO catalyst exhibits abundant Mott–Schottky heterogeneous–interfaces,the well–defined core–shell nanostructure as well as the defective carbon architecture,which provide the multiple guarantees for enhancing the electron transfer and ion/oxygen transport,thus boosting the catalytic ORR and OER activities in neutral electrolyte.As expected,the integrated core–shell Mott–Schottky Co_(9)S_(8)/Co–rGO catalyst delivers the most robust and efficient rechargeable ZABs performance in neutral solution electrolytes accompanied with a power density of 59.5 mW cm^(-2) and superior cycling stability at 5 mA cm^(-2) over 200 h.This work not only emphasizes the rational designing of the high–efficient bifunctional oxygen catalysts from the fundamental understanding of accelerating the electron transfer and ion/oxygen transport,but also sheds light on the practical application prospects in more friendly environmentally neutral rechargeable ZABs.
基金Funding information National Natural Science Foundation of China,Grant/Award Numbers:22179123,21471139Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2020ME038+1 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:201941010National Science Foundation,Division of Materials Research,Grant/Award Number:1938833。
文摘We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,2,5,and 10 A g−1,the SNCC shows reversible capacities of 369,328,249,208,150,and 121 mA h g−1,respectively.Due to a high packing density of 1.01 g cm^(−3),the volumetric capacities are also uniquely favorable,being 373,331,251,210,151,and 122 mA h cm^(−3)at these currents,respectively.SNCC also shows promising initial Coulombic efficiency of 69.0%and extended cycling stability with 99.8%capacity retention after 1000 cycles.As proof of principle,an SNCC-based PIC is fabricated and tested,achieving 94.3Wh kg^(−1)at 237.5Wkg^(−1)and sustaining over 6000 cycles at 30 A g−1 with 84.5%retention.The internal structure of S and N codoped SNCC is based on highly dilated and defective graphene sheets arranged into nanometer-scale walls.Using a baseline S-free carbon for comparison(termed NCC),the role of S doping and the resultant dilated structure was elucidated.According to galvanostatic intermittent titration technique and electrochemical impedance spectroscopy analyses,as well as COMSOL simulations,this structure promotes rapid solid-state diffusion of potassium ions and a solid electrolyte interphase that is stable during cycling.X-ray diffraction was used to probe the ion storage mechanisms in SNCC,establishing the role of reversible potassium intercalation and the presence of KC36,KC24,and KC8 phases at low voltages.
基金funded by the Deutsche Forschungsgemeinschaft DFG and the Sino-German Center for Research Promotion(Grants GZ 1351 and CO 194/19-1)funded by a Chinese Scholarship Council stipend。
文摘First-row(3 d)transition metal oxyhydroxides have attracted increasing attention due to their various advantages.Although investigating the oxidation mechanism and processing such materials into hierarchical architectures are greatly desired for their further development,it remains unclear how the oxidation state change occurs,and efforts to produce hierarchical oxyhydroxides in compliance with high ecological and economic standards have progressed slowly.Here,we describe a facile one-step coprecipitation route for the preparation of hierarchical CoOOH,NiOOH and MnOOH,which involves the diffusion of NH_(3)originating from ammonium hydroxide solution into an aqueous solution containing metal ion salts and K_(2)S_(2)O_(8).Comprehensive characterizations by scanning electron microscope,transmission electron microscopy,X-ray diffraction analysis,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy and in situ p H measurement demonstrated that K_(2)S_(2)O_(8)induces the oxidation state change of metal ion species after the start of hydrolysis.Meanwhile,it was found that,benefiting from the OH–concentration gradient created by the NH_(3)diffusion method and the suitable growth environment provided by the presence of K_(2)S_(2)O_(8)(high nucleation rate and secondary nucleation),the formation of hierarchical oxyhydroxide structures can be realized in aqueous solution at ambient temperature without the use of heat energy and additional structure-directing agents.The hierarchical CoOOH structures are performed as the electrocatalysts for the oxygen evolution reaction in alkaline media,which exhibit good activity with an overpotential of 320 m V at 10 m A cm^(-2)and a low Tafel slope of 59.6 m V dec^(–1),outperforming many congeneric electrocatalysts.Overall,our study not only provides important insights to understand the formation mechanism of hierarchical oxyhydroxides,but also opens up new opportunities for the preparation of hierarchical oxyhydroxides via a facile,green and low-cost method.
基金supported by the National Natural Science Foundation of China(No.22105189).
文摘Cathode interfacial materials(CIMs)stand as critical elemental in organic solar cells(OSCs),which can align energy levels,and foster ohmic contacts between the cathode and active layer of the OSCs.Nevertheless,the lagging advancement in CIMs has concurrently engendered the oversight of theoretical inquiries pertaining to the impact of molecular structure on their performance.Delving into this realm,we present two propeller-shaped isomers,4,4',4''-(benzo[1,2-b:3,4-b':5,6-b'']trithiophene-2,5,8-triyl)tris(2-(3-(dimethylamino)propyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione)(3ONIN)and 6,6',6''-(benzo[1,2-b:3,4-b':5,6-b'']trithiophene-2,5,8-triyl)tris(2-(3-(dimethylamino)propyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione)(3PNIN),distinguished by their molecular planarity,as a promising foundation for crafting highly efficient OSCs.This study illuminates the superiority of 3PNIN with more plane structure,exemplified by its enhanced molar extinction coefficient,deeper lowest unoccupied molecular orbital(LUMO)and highest occupied molecular orbital(HOMO)energy levels,intensified self-doping effect,heightened electron mobility,and elevated conductivity,in comparison to its counterpart,3ONIN.As a result,3PNIN and 3ONIN-treated OSC devices yield efficiencies of 17.73%and 16.82%,respectively.This finding serves as a compelling validation of the critical role played by molecular planarity in influencing CIM performance.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52261145700 and 22279124)the Natural Science Foundation of Shandong Province(No.ZR2020ZD10)the Fundamental Research Funds for the Central Universities(No.202262010).
文摘Oxygen reduction reaction(ORR)plays an important role in the next-generation energy storage technologies,whereas it involves the sluggish and complicated proton-coupled electron transfer(PCET)steps that greatly limit the ORR kinetics.Therefore,it is urgent to construct an efficient catalyst that could simultaneously achieve the rapid oxygen-containing intermediates conversion and fast PCET process but remain challenging.Herein,the adjacent Fe_(3)C nanoparticles coupling with single Fe sites on the bubble-wrap-like porous N-doped carbon(Fe_(3)C@FeSA-NC)were deliberately constructed.Theoretical investigations reveal that the adjacent Fe_(3)C nanoparticles speed up the water dissociation and serve as proton-feeding centers for boosting the ORR kinetics of single Fe sites.Benefiting from the synergistic effect of the Fe_(3)C and single Fe sites,the Fe_(3)C@FeSA-NC affords an excellent half-wave potential of 0.88 V,and enables the assembled Zn-air batteries with the high peak power density of 164.5 mW·cm^(-2)and long-term stability of over 200 h at high current densities at 50 mA·cm^(-2).This work clarifies the mechanism for improving ORR kinetics of single atomic sites by engineering the adjacent proton-feeding centers,shedding light on the rational design of cost-effective electrocatalysts for energy conversion and storage technologies.
基金the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)for funding and supporting this work through Research Partnership Program(No.RP-21-09-75)。
文摘Nanoscale thin-film composite(TFC)polyamide membranes are highly desirable for desalination owing to their excellent separation performance.It is a permanent pursuit to further improve the water flux of membrane without deteriorating the salt rejection.Herein,we fabricated a high-performance polyamide membrane with nanoscale structures through introducing multifunctional crown ether interlayer on the porous substrate impregnated with m-phenylenediamine.The crown ether interlayer can reduce the diffusion of amine monomers to reaction interface influenced by its interaction with m-phenylenediamine and the spatial shielding effect,leading to a controlled interfacial polymerization(IP)reaction.Besides,crown ether with intrinsic cavity is also favorable to adjust the IP process and the microstructure of polyamide layer.Since the outer surface of the nanocavity is lipophilic,crown ether has good solvency with the organic phase,thus attracting more trimesoyl chloride molecules to the interlayer and promoting the IP reaction in the confined space.As a result,a nanoscale polyamide membrane with an ultrathin selective layer of around 50 nm is obtained.The optimal TFC polyamide membrane at crown ether concentration of 0.25 wt.%exhibits a water flux of 61.2 L·m^(−2)·h^(−1),which is 364%of the pristine TFC membrane,while maintaining a rejection of above 97%to NaCl.The development of the tailor-made nanoscale polyamide membrane via constructing multifunctional crown ether interlayer provides a straightforward route to fabricate competitive membranes for highly efficient desalination.
基金The authors extend their appreciation to the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)for funding and supporting this work through Research Partnership Program(No.RP-21-09-75).
文摘Deliberate modulation of the electronic structure via interface engineering is one of promising perspectives to build advanced catalysts for urea oxidation reaction(UOR)at high current densities.However,it still remains some challenges originating from the intrinsically sluggish UOR dynamics and the high energy barrier for urea adsorption.In response,we report the coupled NiSe_(2)nanowrinkles with Ni_(5)P_(4)nanorods heterogeneous structure onto Ni foam(denoted as NiSe_(2)@Ni_(5)P_(4)/NF)through successive phosphorization and selenization strategy,in which the produced closely contacted interface could provide high-flux electron transfer pathways.Theoretical findings decipher that the fast charge transfer takes place at the interfacial region from Ni_(5)P_(4)to NiSe_(2),which is conducive to optimizing adsorption energy of urea molecules.As expected,the well-designed NiSe_(2)@Ni_(5)P_(4)/NF only requires the low potential of 1.402 V at the current density of 500 mA·cm^(-2).More importantly,a small Tafel slope of 27.6 mV·dec^(-1),a high turnover frequency(TOF)value of 1.037 s^(-1)as well as the prolonged stability of 950 h at the current density of 100 mA·cm^(-2)are also achieved.This study enriches the understanding on the electronic structure modulation via interface engineering and offers bright prospect to design advanced UOR catalysts.
基金supported by the National Natural Science Foundation of China(No.52100169)the Natural Science Foundation of Shandong Province(Nos.ZR2020QB196,ZR2022ZD30,and ZR2020QB053).
文摘Single-atom catalysts(SACs)have received considerable attention in hydrogenation of nitroaromatic compounds to aromatic amines.In order to enhance the exposure of single atoms and overcome the mass transfer limitation,construction of hierarchical porous supports for single atoms is highly desirable.Herein,we report a straightforward method to synthesize Co single-atoms supported on a hollow-on-hollow structured carbon monolith(Co_(1)/HOHC-M)by pyrolysis ofα-cellulose monolith loaded with PS-core@ZnCo-zeolite imidazolate frameworks-shell nanospheres(PS@Zn-ZIFs/α-cellulose).The hollow-on-hollow structure consists of a large hollow void with a diameter of~290 nm(derived from the decomposition of polystyrene(PS)nanospheres)and a thin shell with hollow spherical pores with a diameter of~10 nm(derived from the evaporation of ZnO nanoparticles that are in-situ formed during pyrolysis in the presence of CO_(2)fromα-cellulose decomposition).Benefitting from the hierarchically porous architecture,the Co_(1)/HOHC-M exhibits excellent catalytic performance(reaction rate of 421.6 mmol·gCo^(-1)·h^(−1))in the transfer hydrogenation of nitrobenzene to aniline,outperforming the powdered sample of Co_(1)/HCS without the hollow spherical mesopores(reaction rate of 353.8 mmol·gCo^(-1)·h^(−1)).It is expected that this strategy could be well extended in heterogeneous catalysis,given the wide applications of porous carbon-supported single-atom catalysts.
文摘Electrochemistry for energy conversion and catalysis has received unprecedented attention in sustainable society development due to its significant role in renewable energy system construction,which includes the fundamental energy technology of fuel cells and electrical storage devices.To drive a specific electrochemical reaction,highly efficient electrode materials are required which can accelerate the reactions by kinetic improvement or intrinsic activity boosting.It is well known that the"Structure Determines Properties"in chemistry,and to obtain high performance for an electrochemical reaction in energy conversion and catalysis,electrode materials with optimal structure should be probed,and the structure-property correlation should be revealed.All these concerns are very important for electrode materials development.
基金Supported by Capital Application Project on Clinical Characteristics of Science and Technology Commission of Beijing Municipalit (No. Z111107058811056)Planned Project on Beijing Traditional Chinese Medicine "inheritance of 3 + 3 programme" of Beijing Chinese Medicine Administration Bureau (2011-SZ-C-34)
文摘OBJECTIVE:A systematic review of the literature was conducted to evaluate the curative effect and safety of Duhuojisheng Tang on prolapse of the lumbar intervertebral disc.METHODS:The databases of PubMed,China National Knowledge Infrastructure(CNKI),Chinese Scientific Journals Database(VIP),Chinese Biomedical Literature Database(CBM) and Chinese Medical Citation Index(CMCI) were searched up to January 30,2012.Randomized controlled trials were selected to compare Duhuojisheng Tang with one or more of the following treatments:traction,acupuncture,massage,cupping and Western medical treatment.The quality-evaluating standard and the software RevMan 5.1 in Cochrane coordinative net were used to analyze the data.The effective indexes of the results were clinical curative rate,effectiveness of alleviating clinical symptoms and adverse reaction.RESULTS:Thirty-one randomized controlled trials of low quality,involving 3915 patients were systematically evaluated.Statistical analyses showed that good curative effect was achieved in both the group using Duhuojisheng Tang alone and with combined therapies.CONCLUSION:Using Duhuojisheng Tang alone or combined with other therapies can effectively improve pain,leg-raising height and other clinical symptoms of patients with prolapse of lumbar intervertebral disc.Due to low methodological quality of the articles,no exact recommendations can be made.
基金financially supported by the Natural Science Foundation of Shandong Province (ZR2020ZD10)the National Natural Science Foundation of China (21775142)。
文摘Developing highly efficient,easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel.In response,the coupled hierarchical Ni/Fe-based MOF nanosheet arrays with embedded metal sulfide nanoclusters onto nickel foam skeleton(denoted as Fe-Ni_(3)S_(2)@NiFe-MOF/NF)are fabricated,in which the Fe-Ni_(3)S_(2) clusters could effectively restrain the aggregation of the layer metal-organic frameworks(MOF)nanosheets and adjust the local electronic structures of MOFs nanosheets.Benefiting from the rapid charge transfer and the exposure of abundant active sites,the well-designed Fe-Ni_(3)S_(2)@NiFe-MOF/NF displays excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performance.More importantly,when equipped in the alkaline water electrolyzer,the Fe-Ni_(3)S_(2)@Ni Fe-MOF/NF enables the system with a mere 1.6 V for achieving the current density of 10 mA cm^(-2).This work offers a paradigm for designing efficient bifunctional HER/OER electrocatalysts based on the hybrid materials of nanostructured metal sulfide and MOF.
基金the National Natural Science Foundation of China(No.21775142)the Natural Science Foundation of Shandong Province(No.ZR2020ZD10)the Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia(project number 510).
文摘Interface engineering has gradually attracted substantial research interest in constructing active bifunctional catalysts toward urea electrolysis.The fundamental understanding of the crystallinity transition of the components on both sides of the interface is extremely significant for realizing controllable construction of catalysts through interface engineering,but it still remains a challenge.Herein,the Ni/NiO heterogenous nanoparticles are successfully fabricated on the porous N-doped carbon spheres by a facile hydrothermal and subsequent pyrolysis strategy.And for the first time we show the experimental observation that the Ni/NiO interface can be fine-tuned via simply tailoring the heating rate during pyrolysis process,in which the crystalline/amorphous or crystalline/crystalline Ni/NiO heterostructure is deliberately constructed on the porous N-doped carbon spheres(named as CA-Ni/NiO@NCS or CC-Ni/NiO@NCS,respectively).By taking advantage of the unique porous architecture and the synergistic effect between crystalline Ni and amorphous NiO,the well-designed CA-Ni/NiO@NCS displays more remarkable urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity than its crystalline/crystalline counterpart of CC-Ni/NiO@NCS.Particularly,the whole assembled two-electrode electrolytic cell using the elaborate CANi/NiO@NCS both as the anode and cathode can realize the current density of 10 mA·cm^(−2)at a super low voltage of 1.475 V(264 mV less than that of pure water electrolysis),as well as remarkable prolonged stability over 63 h.Besides,the H_(2)evolution driven by an AA battery and a commercial solar cell is also studied to enlighten practical applications for the future.
基金the National Natural Science Foundation of China(Nos.22279124 and 52261145700)Shandong Province Natural Science Foundation(No.ZR2022ZD30)National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.NRF-2020R1A2C3004146 and RS-2023-00235596).
文摘Employing the alkaline water electrolysis system to generate hydrogen holds great prospects but still poses significant challenges,particularly for the construction of hydrogen evolution reaction(HER)catalysts operating at ampere-level current density.Herein,the unique Ru and RuP_(2)dual nano-islands are deliberately implanted on N-doped carbon substrate(denoted as Ru-RuP_(2)/NC),in which a built-in electric field(BEF)is spontaneously generated between Ru-RuP_(2)dual nano-islands driven by their work function difference.Experimental and theoretical results unveil that such constructed BEF could serve as the driving force for triggering fast hydrogen spillover process on bridged Ru-RuP_(2)dual nano-islands,which could invalidate the inhibitory effect of high hydrogen coverage at ampere-level current density,and synchronously speed up the water dissociation on Ru nano-islands and hydrogen adsorption/desorption on RuP_(2)nano-islands through hydrogen spillover process.As a result,the Ru-RuP_(2)/NC affords an ultra-low overpotential of 218 mV to achieve 1.0 A·cm^(−2)along with the superior stability over 1000 h,holding the great promising prospect in practical applications at ampere-level current density.More importantly,this work is the first to advance the scientific understanding of the relationship between the constructed BEF and hydrogen spillover process,which could be enlightening for the rational design of the cost-effective alkaline HER catalysts at ampere-level current density.
