Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-co...Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.展开更多
High-frequency electromagnetic waves and electronic products can bring great convenience to people’s life,but lead to a series of electromagnetic interference(EMI)problems,such as great potential dangers to the norma...High-frequency electromagnetic waves and electronic products can bring great convenience to people’s life,but lead to a series of electromagnetic interference(EMI)problems,such as great potential dangers to the normal operation of elec-tronic components and human safety.Therefore,the research of EMI shield-ing materials has attracted extensive attention by the scholars.Among them,polymer-based EMI shielding materials with light weight,high specific strength,and stable properties have become the current mainstream.The construction of 3D conductive networks has proved to be an effective method for the prepara-tion of polymer-based EMI shielding materials with excellent shielding effective-ness(SE).In this paper,the shielding mechanism of polymer-based EMI shield-ing materials with 3D conductive networks is briefly introduced,with emphasis on the preparation methods and latest research progress of polymer-based EMI shielding materials with different 3D conductive networks.The key scientific and technical problems to be solved in the field of polymer-based EMI shielding materials are also put forward.Finally,the development trend and application prospects of polymer-based EMI shielding materials are prospected.展开更多
The development of bifunctional electrocatalysts with high activity and stability for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is crucial for efficient overall water splitting but still challe...The development of bifunctional electrocatalysts with high activity and stability for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is crucial for efficient overall water splitting but still challenging.Herein,we propose a facile and effective polymerization–pyrolysis–selenization(PPS)strategy for in-situ synthesis of N-doped carbon nanosnakes(NCNSs)encapsulated Fe-doped CoSe nanoparticles(NPs)derived from predesigned trimetallic Zn/Fe/Co polyphthalocyanine conjugated polymer networks.Benefiting from the synergistic effect between the regulation of Fe atoms and CoSe NPs as well as the confinement effect of in situ formed porous conductive carbon nanosnakes,the FeCoSe@NCNSs catalyst exhibited the excellent electrocatalytic activity for HER with small overpotentials(142 and 99 mV in 0.5 M H_(2)SO_(4) and 1 M KOH)and OER(320 mV in 1 M KOH)at the current density of 10 mA cm^(-2).Particularly,it also can be used as an efficient bifunctional electrocatalyst with a cell voltage of 1.66 V to achieve a current density of 10 mA cm^(-2) and superior stability for overall water splitting.Density functional theory study reveals that the doping of Fe atoms on Co Se enhanced the splitting and delocalization of metal-d orbitals close Fermi level,and modifies the distribution of Se-p orbitals close Fermi level,which improved the flexibility of electron donor-acceptor system and the hydrogen adsorption free energy change on metal-metal bridge sites in FeCoSe@NCNSs.Additionally,beneficial from the accepting of Fe-Se bridge site,the overpotential of OER which following intramolecular oxygen coupling mechanism is also decreased,thus accelerating the electrocatalytic performance.This work presents a novel strategy to regulate the activity and stability of transition metal selenides and facilitating the rational design of bifunctional electrocatalysts for overall water splitting applications.展开更多
Over the past decades,solid electrolytes have re-emerged as promising candidates which replace flammable liquid electrolytes for a safe,energy-dense,and reversible storage of electrochemical energy in batteries[1].How...Over the past decades,solid electrolytes have re-emerged as promising candidates which replace flammable liquid electrolytes for a safe,energy-dense,and reversible storage of electrochemical energy in batteries[1].However,as the main distinct families of solid electrolytes,both polymer and ceramic electrolytes have their individual disadvantages in ionic conductivity,mechanical robustness,and interfacial resistance.展开更多
Electrochemical coupling hydrogen evolution with biomass reforming reaction(named electrochemical hydrogen and chemical cogeneration(EHCC)),which realizes green hydrogen production and chemical upgrading simultaneousl...Electrochemical coupling hydrogen evolution with biomass reforming reaction(named electrochemical hydrogen and chemical cogeneration(EHCC)),which realizes green hydrogen production and chemical upgrading simultaneously,is a promising method to build a carbon-neutral society.Herein,we analyze the EHCC process by considering the market assessment.The ethanol to acetic acid and hydrogen approach is the most feasible for large-scale hydrogen production.We develop AuCu nanocatalysts,which can selectively oxidize ethanol to acetic acid(>97%)with high long-term activity.The isotopic and in-situ infrared experiments reveal that the promoted water dissociation step by alloying contributes to the enhanced activity of the partial oxidation reaction path.A flow-cell electrolyzer equipped with the AuCu anodic catalyst achieves the steady production of hydrogen and acetic acid simultaneously in both high selectivity(>90%),demonstrating the potential scalable application for green hydrogen production with low energy consumption and high profitability.展开更多
The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving c...The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.展开更多
The impeded mass transfer rate by on-site-generated gas bubbles at both cathode and anode dramatically reduces the energy conversion efficiency of the proton exchange membrane water electrolyzer(PEMWE).Herein,we repor...The impeded mass transfer rate by on-site-generated gas bubbles at both cathode and anode dramatically reduces the energy conversion efficiency of the proton exchange membrane water electrolyzer(PEMWE).Herein,we report a surfactant-assistant method to accelerate the nano/micro-bubble detachment and the mass transfer rate by reducing the surface tension,resulting in an increase in overall efficiency.Four kinds of surfactants are studied in this work.Only potassium perfluorobutyl sulfonate(PPFBS),which has the structural similarity to Nafion,shows a significant promotion of activity and stability for both hygrogen evolution reaction(HER)and oxygen evolution reaction(OER)in the acidic medium at the high current density region.The HER overpotential at 0.1 A·cm−2 decreased 22%,and the current density at−0.4 V increased 31%by adding PPFBS.The promotion of overall efficiency by PPFBS on a homemade PEMWE was also proven.The reduced surface tension and electrostatic repulsion were the probable origins of the accelerated bubble detachment.展开更多
Dynamic polymers with both physical interactions and dynamic covalent bonds exhibit superior performance,but achieving such dry polymers in an effi-cient manner remains a challenge.Herein,we report a novel organic sol...Dynamic polymers with both physical interactions and dynamic covalent bonds exhibit superior performance,but achieving such dry polymers in an effi-cient manner remains a challenge.Herein,we report a novel organic solvent quenched polymer synthesis using the natural molecule thioctic acid(TA),which has both a dynamic disulfide bond and carboxylic acid.The effects of the solvent type and concentration along with reaction times on the proposed reaction were thoroughly explored for polymer synthesis.Solid-state proton nuclear magnetic resonance(1 H NMR)and first-principles simulations were carried out to investigate the reaction mechanism.They show that the chlorinated solvent can efficiently stabilize and mediate the depolymerization of poly(TA),which is more kinetically favorable upon lowering the temperature.Attributed to the numerous dynamic covalent disulfide bonds and noncovalent hydrogen bonds,the obtained poly(TA)shows high extensibility,self-healing,and reprocessable properties.It can also be employed as an efficient adhesive even on a Teflon surface and 3D printed using the fused deposition modeling technique.This new polymer synthesis approach of using organic solvents as catalysts along with the unique reaction mechanism provides a new pathway for efficient polymer synthesis,especially for multifunctional dynamic polymers.展开更多
The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction(ORR)is intensively increasing.Herein,single-atomic copper sites supported on...The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction(ORR)is intensively increasing.Herein,single-atomic copper sites supported on N-doped three-dimensional hierarchically porous carbon catalyst(Cu_(1)/NC)was prepared by coordination pyrolysis strategy.Remarkably,the Cu_(1)/NC-900 catalyst not only exhibits excellent ORR performance with a half-wave potential of 0.894 V(vs.RHE)in alkaline media,outperforming those of commercial Pt/C(0.851 V)and Cu nanoparticles anchored on N-doped porous carbon(CuNPs/NC-900),but also demonstrates high stability and methanol tolerance.Moreover,the Cu_(1)/NC-900 based Zn-air battery exhibits higher power density,rechargeability and cyclic stability than the one based on Pt/C.Both experimental and theoretical investigations demonstrated that the excellent performance of the as-obtained Cu_(1)/NC-900 could be attributed to the synergistic effect between copper coordinated by three N atoms active sites and the neighbouring carbon defect,resulting in elevated Cu d-band centers of Cu atoms and facilitating intermediate desorption for ORR process.This study may lead towards the development of highly efficient non-noble metal catalysts for applications in electrochemical energy conversion.展开更多
Developing non-precious metal catalysts with high activity and stability for electrochemical hydrogen evolution reaction(HER)is of great significance in both scie nee and tech no logy.In this work,N-doped CMK-3,which ...Developing non-precious metal catalysts with high activity and stability for electrochemical hydrogen evolution reaction(HER)is of great significance in both scie nee and tech no logy.In this work,N-doped CMK-3,which was prepared with a casting method using SBA-15 as thehard template and ammonia as the nitrogen source,has been utilized to hold MoS2 and restrict its growth to form MoS2@N-CMK-3 composite.As a result,M0S2 was found to have poorly crystallized and the limited space of porous N-CMK-3 made its size much small.Then there are moreactive sites in MoS2.Accordingly,MoS2@N-CMK-3 has exhibited good electrocatalytic performance toward HER in acids with a quite small Tafelslope of 32 mV·dec^-1.And more importantly,compared to MoS2@CMK-3,its stability has been greatly improved,which can be attributedto the interaction between M0S2 and nitrogen atoms avoiding aggregation and mass loss.This work provides an idea that doping a porouscarbon support with nitrogen is an effective way to enhance the stability of the catalyst.展开更多
The development of efficient and cost-effective oxygen evolution reaction(OER)electrocatalysts is crucial for clean energy conversion and storage devices,such as water-splitting,CO_(2) reduction,and metalair batteries...The development of efficient and cost-effective oxygen evolution reaction(OER)electrocatalysts is crucial for clean energy conversion and storage devices,such as water-splitting,CO_(2) reduction,and metalair batteries.Herein,we report an efficient 2-dimensional OER catalyst of ultrathin nickel-iron sulfide nanosheets(Ni Fe S-NS).Dodecanethiol is employed in the synthesis,which prohibits the growth along the Z-axis,thus a nanosheet is obtained.The Ni Fe S-NS shows high OER catalytic activity,which only requires a small overpotential of 273 mV to achieve the OER current density of 10 mA/cm^(2) in alkaline electrolyte,and almost no decay after 150 h of chronopotentiometry test.The high performance is attributed to the 2-dimensional structure,the synergistic effect from the Ni and Fe components which promotes the formation of the high valence Ni species,and the tuning effect from the in-situ generated sulfate doping.This work demonstrates the advantages of the 2-dimensional sulfides in electrocatalysis.展开更多
Electrochemical upgrading of biomass ethanol to value-added chemicals is promising for sustainable society.Here,we synthesize defective Ni_(3)S_(2) nanowires(NWs),which show high activity towards electrochemical oxida...Electrochemical upgrading of biomass ethanol to value-added chemicals is promising for sustainable society.Here,we synthesize defective Ni_(3)S_(2) nanowires(NWs),which show high activity towards electrochemical oxidation of ethanol to acetate.The Ni_(3)S_(2) NWs are formed by the oriented attachment mechanism,and rich defects are introduced during the growth.A low onset potential of 1.31 V and high mass activity of 8,716 mA·mgNi^(-1) at 1.5 V are achieved using the synthesized Ni_(3)S_(2) NWs toward the ethanol electro-oxidation,which are better than the Ni(OH)2 NWs and the Ni_(3)S_(2) nanoparticles(NPs).And the selectivity for the acetate generation is ca.99%.The high activity of Ni_(3)S_(2) NWs is attributed to the easier oxidation of Ni(II)to the catalytically active Ni(III)species with the promotion from S component and rich defects.These results demonstrate that the defective NWs can be synthesized by the oriented attachment method and the defective Ni_(3)S_(2) NWs structure as the efficient nonnoble metal electrocatalysts for oxidative upgrading of ethanol.展开更多
Herein,graphene oxide(GO)-encapsulated silica(SiO 2)hybrids(GO@SiO 2)were prepared via electrostatic self-assembly of the 3-aminopropyltriethoxysilane(APS)-modified SiO_(2) and GO.The as-prepared GO@SiO 2 was introduc...Herein,graphene oxide(GO)-encapsulated silica(SiO 2)hybrids(GO@SiO 2)were prepared via electrostatic self-assembly of the 3-aminopropyltriethoxysilane(APS)-modified SiO_(2) and GO.The as-prepared GO@SiO 2 was introduced into polydimethyl-siloxane(PDMS)elastomer to simultaneously increase the dielectric constant(k)and mechanical properties of PDMS.Then,the in situ thermal reduction of GO@SiO_(2)/PDMS composites was conducted at 180℃ for 2 h to increase the interfacial polariz-ability of GO@SiO_(2).As a result,the values of k at 1000 Hz are largely improved from 3.2 for PDMS to 13.3 for the reduced GO@SiO_(2)(RGO@SiO_(2))/PDMS elastomer.Meanwhile,the dielectric loss of the composites remains low(<0.2 at 1000 Hz).More importantly,the actuated strain at low electric field(5 kV/mm)obviously increases from 0.3%for pure PDMS to 2.59%for the composites with 60 phr of RGO@SiO_(2),an eightfold increase in the actuated strain.In addition,both the tensile strength and elastic modulus are obviously improved by adding 60 phr of RGO@SiO_(2),indicating a good reinforcing effect of RGO@SiO_(2) on PDMS.Our goal is to develop a simple and effective way to improve the actuated performance and mechanical strength of the PDMS dielectric elastomer for its wider application.展开更多
Owing to the importance of drug delivery in cancer or other diseases' therapy, the targeted drug delivery (TDD) system has been attracting enormous interest. Herein, we model the TDD system and design a novel rod-...Owing to the importance of drug delivery in cancer or other diseases' therapy, the targeted drug delivery (TDD) system has been attracting enormous interest. Herein, we model the TDD system and design a novel rod-like nanocarrier by using the coarse grained model-based density functional theory, which combines a modified fundamental measure theory for the excluded-volume effects, Wertheim's first-order thermodynamics perturbation theory for the chain connectivity and the mean field approximation for van der Waals attraction. For comparison, the monomer nanocarrier TDD system and the no nanocarrier one are also investigated. The results indicate that the drug delivery capacity of rod-like nanocarriers is about 62 times that of the no nanocarrier one, and about 6 times that of the monomer nanocarriers. The reason is that the rod-like nanocarriers would self-assemble into the smectic phase perpendicular to the membrane surface. It is the self-assembly of the rod-like nanocarriers that yields the driving force for the targeted delivery of drugs inside the cell membrane. By contrast, the conventional monomer nanocarrier drug delivery system lacks the driving force to deliver the drugs into the cell membrane. In short, the novel rod-like nanocarrier TDD system may improve the drug delivery efficiency. Although the model in this work is simple, it is expected that the system may provide a new perspective for cancer targeted therapy.展开更多
Water electrolysis has been regarded as a promising technology to produce clean hydrogen fuel with high purity. However, large-scale water electrolysis has been greatly hindered due to the lack of non-noble metal cata...Water electrolysis has been regarded as a promising technology to produce clean hydrogen fuel with high purity. However, large-scale water electrolysis has been greatly hindered due to the lack of non-noble metal catalysts with high catalytic performance. Benefitting from unique hollow structures with large surface area and adjustable chemical compositions, hollow design plays an important role in improving the electrocatalytic performance for hydrogen evolution reaction(HER). Herein, we report an effective multi-step strategy to prepare hierarchical Co-decorated Mo_(2)C hollow spheres(CMCHSs) as electrocatalyst for HER. To be specific, the preparation process involves a metal-chelated polymerization and a subsequent surface modulation process. Owing to the unique hollow structure and incorporation of Co species,the as-prepared CMCHSs demonstrate largely enhanced HER performance with a low overpotential of 139 mV at the current density of 10 m A·cm^(-2) and good cycling durability in acid. The present research work highlights a new feasible strategy for the design of HER electrocatalyst via hollow designs and surface engineering.展开更多
Ag is a potential low-cost oxygen reduction reaction(ORR)catalyst in alkaline condition,which is important for the zinc-air batteries.Here,we report that an Ag based single atom catalyst with heteroatom coordination.A...Ag is a potential low-cost oxygen reduction reaction(ORR)catalyst in alkaline condition,which is important for the zinc-air batteries.Here,we report that an Ag based single atom catalyst with heteroatom coordination.Ag1-h-NPClSC,has been synthesized and shown much improved performance towards ORR by manipulating the coordination environment of the Ag center.It shows a high half wave potential(0.896 V)and a high turnover frequency(TOF)(5.9 s^(−1))at 0.85 V,which are higher than the previously reported Ag based catalysts and commercial Pt/C.A zinc-air battery with high peak power density of 270 mW·cm^(−2)is fabricated by using the Ag1-h-NPClSC as air electrode.The high performance is attributed to(1)the hollow structure providing good mass transfer;(2)the single atom metal center structure providing high utility of the Ag;(3)heteroatom coordination environment providing the adjusted binding to the ORR intermediates.Density functional theory(DFT)calculations show that the energy barrier for the formation of OOH*,which is considered as the rate determine step for ORR on Ag nanoparticles,is lowered on Ag1-h-NPClSC,thus improving the ORR activity.This work demonstrates that the well manipulated Ag based single atom catalysts are promising in electrocatalysis.展开更多
基金supports received from the National Natural Science Foundation of China (21776301,21636009)are gratefully acknowledged.
文摘Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.
基金Foundation of National Natural Science Foundation of China,Grant/Award Number:51903145Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China,Grant/Award Number:2019JC-11Wang L.would like to thank the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,Grant/Award Number:CX202053。
文摘High-frequency electromagnetic waves and electronic products can bring great convenience to people’s life,but lead to a series of electromagnetic interference(EMI)problems,such as great potential dangers to the normal operation of elec-tronic components and human safety.Therefore,the research of EMI shield-ing materials has attracted extensive attention by the scholars.Among them,polymer-based EMI shielding materials with light weight,high specific strength,and stable properties have become the current mainstream.The construction of 3D conductive networks has proved to be an effective method for the prepara-tion of polymer-based EMI shielding materials with excellent shielding effective-ness(SE).In this paper,the shielding mechanism of polymer-based EMI shield-ing materials with 3D conductive networks is briefly introduced,with emphasis on the preparation methods and latest research progress of polymer-based EMI shielding materials with different 3D conductive networks.The key scientific and technical problems to be solved in the field of polymer-based EMI shielding materials are also put forward.Finally,the development trend and application prospects of polymer-based EMI shielding materials are prospected.
基金supported by the Taishan Scholars Program of Shandong Province (No. tsqn201909065)the National Natural Science Foundation of China (No. 22108306)+3 种基金the Shandong Provincial Natural Science Foundation (ZR2020QB174, ZR2021YQ15)the Postgraduate Innovation Fund of China University of Petroleum(East China)(No. YCX2020037)the State Key Laboratory of Organic-Inorganic Composites (oic-202101006)the Key Laboratory of Functional Inorganic Material Chemistry (Heilongjiang University),Ministry of Education。
文摘The development of bifunctional electrocatalysts with high activity and stability for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is crucial for efficient overall water splitting but still challenging.Herein,we propose a facile and effective polymerization–pyrolysis–selenization(PPS)strategy for in-situ synthesis of N-doped carbon nanosnakes(NCNSs)encapsulated Fe-doped CoSe nanoparticles(NPs)derived from predesigned trimetallic Zn/Fe/Co polyphthalocyanine conjugated polymer networks.Benefiting from the synergistic effect between the regulation of Fe atoms and CoSe NPs as well as the confinement effect of in situ formed porous conductive carbon nanosnakes,the FeCoSe@NCNSs catalyst exhibited the excellent electrocatalytic activity for HER with small overpotentials(142 and 99 mV in 0.5 M H_(2)SO_(4) and 1 M KOH)and OER(320 mV in 1 M KOH)at the current density of 10 mA cm^(-2).Particularly,it also can be used as an efficient bifunctional electrocatalyst with a cell voltage of 1.66 V to achieve a current density of 10 mA cm^(-2) and superior stability for overall water splitting.Density functional theory study reveals that the doping of Fe atoms on Co Se enhanced the splitting and delocalization of metal-d orbitals close Fermi level,and modifies the distribution of Se-p orbitals close Fermi level,which improved the flexibility of electron donor-acceptor system and the hydrogen adsorption free energy change on metal-metal bridge sites in FeCoSe@NCNSs.Additionally,beneficial from the accepting of Fe-Se bridge site,the overpotential of OER which following intramolecular oxygen coupling mechanism is also decreased,thus accelerating the electrocatalytic performance.This work presents a novel strategy to regulate the activity and stability of transition metal selenides and facilitating the rational design of bifunctional electrocatalysts for overall water splitting applications.
文摘Over the past decades,solid electrolytes have re-emerged as promising candidates which replace flammable liquid electrolytes for a safe,energy-dense,and reversible storage of electrochemical energy in batteries[1].However,as the main distinct families of solid electrolytes,both polymer and ceramic electrolytes have their individual disadvantages in ionic conductivity,mechanical robustness,and interfacial resistance.
基金supported by the National Natural Science Foundation of China(Nos.21971008 and 22279004)Beijing Natural Science Foundation(No.Z210016)Fundamental Research Funds for the Central Universities(No.buctrc201916).
文摘Electrochemical coupling hydrogen evolution with biomass reforming reaction(named electrochemical hydrogen and chemical cogeneration(EHCC)),which realizes green hydrogen production and chemical upgrading simultaneously,is a promising method to build a carbon-neutral society.Herein,we analyze the EHCC process by considering the market assessment.The ethanol to acetic acid and hydrogen approach is the most feasible for large-scale hydrogen production.We develop AuCu nanocatalysts,which can selectively oxidize ethanol to acetic acid(>97%)with high long-term activity.The isotopic and in-situ infrared experiments reveal that the promoted water dissociation step by alloying contributes to the enhanced activity of the partial oxidation reaction path.A flow-cell electrolyzer equipped with the AuCu anodic catalyst achieves the steady production of hydrogen and acetic acid simultaneously in both high selectivity(>90%),demonstrating the potential scalable application for green hydrogen production with low energy consumption and high profitability.
基金financial support from the King Abdullah University of Science and Technology(KAUST).
文摘The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.
基金This work was supported by the National Natural Science Foundation of China(Nos.21971008 and 22101016)Fundamental Research Funds for the Central Universities(buctrc201916,buctrc201823)China Petroleum&Chemical Corporation(SINOPEC,120052-2).
文摘The impeded mass transfer rate by on-site-generated gas bubbles at both cathode and anode dramatically reduces the energy conversion efficiency of the proton exchange membrane water electrolyzer(PEMWE).Herein,we report a surfactant-assistant method to accelerate the nano/micro-bubble detachment and the mass transfer rate by reducing the surface tension,resulting in an increase in overall efficiency.Four kinds of surfactants are studied in this work.Only potassium perfluorobutyl sulfonate(PPFBS),which has the structural similarity to Nafion,shows a significant promotion of activity and stability for both hygrogen evolution reaction(HER)and oxygen evolution reaction(OER)in the acidic medium at the high current density region.The HER overpotential at 0.1 A·cm−2 decreased 22%,and the current density at−0.4 V increased 31%by adding PPFBS.The promotion of overall efficiency by PPFBS on a homemade PEMWE was also proven.The reduced surface tension and electrostatic repulsion were the probable origins of the accelerated bubble detachment.
基金research at the Oak Ridge National Laboratory,managed by UT Battelle,LLC,for the U.S.Department of Energy(DOE)under Contract No.DE-AC05-00OR22725sponsored by the Laboratory Directed Research and Development Program at Oak Ridge National Laboratory.P.-F.C.acknowledges financial support by Fundamental Research Funds for the Central Universities(buctrc202222)。
文摘Dynamic polymers with both physical interactions and dynamic covalent bonds exhibit superior performance,but achieving such dry polymers in an effi-cient manner remains a challenge.Herein,we report a novel organic solvent quenched polymer synthesis using the natural molecule thioctic acid(TA),which has both a dynamic disulfide bond and carboxylic acid.The effects of the solvent type and concentration along with reaction times on the proposed reaction were thoroughly explored for polymer synthesis.Solid-state proton nuclear magnetic resonance(1 H NMR)and first-principles simulations were carried out to investigate the reaction mechanism.They show that the chlorinated solvent can efficiently stabilize and mediate the depolymerization of poly(TA),which is more kinetically favorable upon lowering the temperature.Attributed to the numerous dynamic covalent disulfide bonds and noncovalent hydrogen bonds,the obtained poly(TA)shows high extensibility,self-healing,and reprocessable properties.It can also be employed as an efficient adhesive even on a Teflon surface and 3D printed using the fused deposition modeling technique.This new polymer synthesis approach of using organic solvents as catalysts along with the unique reaction mechanism provides a new pathway for efficient polymer synthesis,especially for multifunctional dynamic polymers.
基金This work was financially supported by the National Key Research and Development Program of China （No. 2017YFA0206500）, the National Natural Science Foundation of China （No. 21671014）, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology （No. oic-201503003） and the Fundamental Research Funds for the Central Universities （No. buctrc201522）.
文摘高效甲醇氧化反应(粗腐殖质) 催化剂对吸引人的、直接甲醇燃料房间的表演批评。这里，我们使用表面学习 MOR 机制并且给的模型催化剂推进指导到新高效粗腐殖质催化剂的设计的控制 PtNi 合金 nanoparticles。PtNi 合金的提高的粗腐殖质活动主要被归因于提高哦由于表面 Ni 地点的吸附。这建议 MOR 经历 Langmuir-Hinshelwood 机制，由此吸附了公司，与帮助被移开吸附哦。在 PtNi 催化剂以内，磅提供甲醇吸附地点(在哪个甲醇被变换成吸附的公司) 并且 Ni 提供哦吸附地点。为粗腐殖质的优化 Pt-Ni 比率被发现是 1:1。这建议那 bifunctional 有公司的催化剂并且哦吸附地点能导致高度活跃的粗腐殖质催化剂。
基金financially supported by the National Key Research and Development Program of China (2017YFA0206500)the National Natural Science Foundation of China (21671014)the Fundamental Research Funds for the Central Universities (buctrc201823)
基金the National Natural Science Foundation of China(Nos.21804319,21971002)the Natural Science Foundation of Anhui province(Nos.1908085QB45 and 2008085QB81)the Education Departm ent of Anhui Province Foundation(No.KJ2019A0503).We thank the BL14W1 station in Shanghai Synchrotron Radiation Facility(SSRF)and 1W1B station for XAFS measurement in Beijing Synchrotron Radiation Facility(BSRF).The calculations in this paper have been done on the supercomputing system of the National Supercomputing Center in Changsha.
文摘The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction(ORR)is intensively increasing.Herein,single-atomic copper sites supported on N-doped three-dimensional hierarchically porous carbon catalyst(Cu_(1)/NC)was prepared by coordination pyrolysis strategy.Remarkably,the Cu_(1)/NC-900 catalyst not only exhibits excellent ORR performance with a half-wave potential of 0.894 V(vs.RHE)in alkaline media,outperforming those of commercial Pt/C(0.851 V)and Cu nanoparticles anchored on N-doped porous carbon(CuNPs/NC-900),but also demonstrates high stability and methanol tolerance.Moreover,the Cu_(1)/NC-900 based Zn-air battery exhibits higher power density,rechargeability and cyclic stability than the one based on Pt/C.Both experimental and theoretical investigations demonstrated that the excellent performance of the as-obtained Cu_(1)/NC-900 could be attributed to the synergistic effect between copper coordinated by three N atoms active sites and the neighbouring carbon defect,resulting in elevated Cu d-band centers of Cu atoms and facilitating intermediate desorption for ORR process.This study may lead towards the development of highly efficient non-noble metal catalysts for applications in electrochemical energy conversion.
基金This work was supported by the Nature Science Foundation of Zhejiang Province(No.LY20B010004)and the National Natural Science Foundation of China(Nos.21671152,51672193,51420105002, 21671014).
文摘Developing non-precious metal catalysts with high activity and stability for electrochemical hydrogen evolution reaction(HER)is of great significance in both scie nee and tech no logy.In this work,N-doped CMK-3,which was prepared with a casting method using SBA-15 as thehard template and ammonia as the nitrogen source,has been utilized to hold MoS2 and restrict its growth to form MoS2@N-CMK-3 composite.As a result,M0S2 was found to have poorly crystallized and the limited space of porous N-CMK-3 made its size much small.Then there are moreactive sites in MoS2.Accordingly,MoS2@N-CMK-3 has exhibited good electrocatalytic performance toward HER in acids with a quite small Tafelslope of 32 mV·dec^-1.And more importantly,compared to MoS2@CMK-3,its stability has been greatly improved,which can be attributedto the interaction between M0S2 and nitrogen atoms avoiding aggregation and mass loss.This work provides an idea that doping a porouscarbon support with nitrogen is an effective way to enhance the stability of the catalyst.
基金supported by the National Key Research and Development Program of China(No.2019YFA0210300)National Natural Science Foundation of China(No.21971008)Fundamental Research Funds for the Central Universities(Nos.buctrc201916,buctrc201823)。
文摘The development of efficient and cost-effective oxygen evolution reaction(OER)electrocatalysts is crucial for clean energy conversion and storage devices,such as water-splitting,CO_(2) reduction,and metalair batteries.Herein,we report an efficient 2-dimensional OER catalyst of ultrathin nickel-iron sulfide nanosheets(Ni Fe S-NS).Dodecanethiol is employed in the synthesis,which prohibits the growth along the Z-axis,thus a nanosheet is obtained.The Ni Fe S-NS shows high OER catalytic activity,which only requires a small overpotential of 273 mV to achieve the OER current density of 10 mA/cm^(2) in alkaline electrolyte,and almost no decay after 150 h of chronopotentiometry test.The high performance is attributed to the 2-dimensional structure,the synergistic effect from the Ni and Fe components which promotes the formation of the high valence Ni species,and the tuning effect from the in-situ generated sulfate doping.This work demonstrates the advantages of the 2-dimensional sulfides in electrocatalysis.
基金This work was supported by the National Natural Science Foundation of China(No.21971008)the Fundamental Research Funds for the Central Universities(buctrc201916,buctrc201823).
文摘Electrochemical upgrading of biomass ethanol to value-added chemicals is promising for sustainable society.Here,we synthesize defective Ni_(3)S_(2) nanowires(NWs),which show high activity towards electrochemical oxidation of ethanol to acetate.The Ni_(3)S_(2) NWs are formed by the oriented attachment mechanism,and rich defects are introduced during the growth.A low onset potential of 1.31 V and high mass activity of 8,716 mA·mgNi^(-1) at 1.5 V are achieved using the synthesized Ni_(3)S_(2) NWs toward the ethanol electro-oxidation,which are better than the Ni(OH)2 NWs and the Ni_(3)S_(2) nanoparticles(NPs).And the selectivity for the acetate generation is ca.99%.The high activity of Ni_(3)S_(2) NWs is attributed to the easier oxidation of Ni(II)to the catalytically active Ni(III)species with the promotion from S component and rich defects.These results demonstrate that the defective NWs can be synthesized by the oriented attachment method and the defective Ni_(3)S_(2) NWs structure as the efficient nonnoble metal electrocatalysts for oxidative upgrading of ethanol.
基金financially supported by the National Key R&D Program of China(2018YFA0306900 and 2018YFA0305800)the National Natural Science Foundation of China(51872012)。
基金We would like to express our sincere thanks to the National Natural Science Foundation of China[grant number 51173007],[grant number 51103090],[grant number 51221002]for financial support.
文摘Herein,graphene oxide(GO)-encapsulated silica(SiO 2)hybrids(GO@SiO 2)were prepared via electrostatic self-assembly of the 3-aminopropyltriethoxysilane(APS)-modified SiO_(2) and GO.The as-prepared GO@SiO 2 was introduced into polydimethyl-siloxane(PDMS)elastomer to simultaneously increase the dielectric constant(k)and mechanical properties of PDMS.Then,the in situ thermal reduction of GO@SiO_(2)/PDMS composites was conducted at 180℃ for 2 h to increase the interfacial polariz-ability of GO@SiO_(2).As a result,the values of k at 1000 Hz are largely improved from 3.2 for PDMS to 13.3 for the reduced GO@SiO_(2)(RGO@SiO_(2))/PDMS elastomer.Meanwhile,the dielectric loss of the composites remains low(<0.2 at 1000 Hz).More importantly,the actuated strain at low electric field(5 kV/mm)obviously increases from 0.3%for pure PDMS to 2.59%for the composites with 60 phr of RGO@SiO_(2),an eightfold increase in the actuated strain.In addition,both the tensile strength and elastic modulus are obviously improved by adding 60 phr of RGO@SiO_(2),indicating a good reinforcing effect of RGO@SiO_(2) on PDMS.Our goal is to develop a simple and effective way to improve the actuated performance and mechanical strength of the PDMS dielectric elastomer for its wider application.
基金supported by the National Natural Science Foundation of China (20874005, 20736002, 20821004)the National Basic Research Program of China (2011CB706900)+1 种基金Huo Yingdong Fundamental Research Foundation (121070)Novel Team (IRT0807) from Ministry of Education and the Chemical Grid Project of BUCT
文摘Owing to the importance of drug delivery in cancer or other diseases' therapy, the targeted drug delivery (TDD) system has been attracting enormous interest. Herein, we model the TDD system and design a novel rod-like nanocarrier by using the coarse grained model-based density functional theory, which combines a modified fundamental measure theory for the excluded-volume effects, Wertheim's first-order thermodynamics perturbation theory for the chain connectivity and the mean field approximation for van der Waals attraction. For comparison, the monomer nanocarrier TDD system and the no nanocarrier one are also investigated. The results indicate that the drug delivery capacity of rod-like nanocarriers is about 62 times that of the no nanocarrier one, and about 6 times that of the monomer nanocarriers. The reason is that the rod-like nanocarriers would self-assemble into the smectic phase perpendicular to the membrane surface. It is the self-assembly of the rod-like nanocarriers that yields the driving force for the targeted delivery of drugs inside the cell membrane. By contrast, the conventional monomer nanocarrier drug delivery system lacks the driving force to deliver the drugs into the cell membrane. In short, the novel rod-like nanocarrier TDD system may improve the drug delivery efficiency. Although the model in this work is simple, it is expected that the system may provide a new perspective for cancer targeted therapy.
基金financially supported by the National Natural Science Foundation of China (No.51902016)the Fundamental Research Funds for the Central Universities (Nos.buctrc201829 and buctrc201904)the "Double-First Class" Construction Projects (No.XK1804-02)。
文摘Water electrolysis has been regarded as a promising technology to produce clean hydrogen fuel with high purity. However, large-scale water electrolysis has been greatly hindered due to the lack of non-noble metal catalysts with high catalytic performance. Benefitting from unique hollow structures with large surface area and adjustable chemical compositions, hollow design plays an important role in improving the electrocatalytic performance for hydrogen evolution reaction(HER). Herein, we report an effective multi-step strategy to prepare hierarchical Co-decorated Mo_(2)C hollow spheres(CMCHSs) as electrocatalyst for HER. To be specific, the preparation process involves a metal-chelated polymerization and a subsequent surface modulation process. Owing to the unique hollow structure and incorporation of Co species,the as-prepared CMCHSs demonstrate largely enhanced HER performance with a low overpotential of 139 mV at the current density of 10 m A·cm^(-2) and good cycling durability in acid. The present research work highlights a new feasible strategy for the design of HER electrocatalyst via hollow designs and surface engineering.
基金the National Key Research and Development Program of China(No.2019YFA0210300)the National Natural Science Foundation of China(No.21971008)Fundamental Research Funds for the Central Universities(Nos.buctrc201916 and buctrc201823).
文摘Ag is a potential low-cost oxygen reduction reaction(ORR)catalyst in alkaline condition,which is important for the zinc-air batteries.Here,we report that an Ag based single atom catalyst with heteroatom coordination.Ag1-h-NPClSC,has been synthesized and shown much improved performance towards ORR by manipulating the coordination environment of the Ag center.It shows a high half wave potential(0.896 V)and a high turnover frequency(TOF)(5.9 s^(−1))at 0.85 V,which are higher than the previously reported Ag based catalysts and commercial Pt/C.A zinc-air battery with high peak power density of 270 mW·cm^(−2)is fabricated by using the Ag1-h-NPClSC as air electrode.The high performance is attributed to(1)the hollow structure providing good mass transfer;(2)the single atom metal center structure providing high utility of the Ag;(3)heteroatom coordination environment providing the adjusted binding to the ORR intermediates.Density functional theory(DFT)calculations show that the energy barrier for the formation of OOH*,which is considered as the rate determine step for ORR on Ag nanoparticles,is lowered on Ag1-h-NPClSC,thus improving the ORR activity.This work demonstrates that the well manipulated Ag based single atom catalysts are promising in electrocatalysis.
