Constructing heterointerface engineering has becoming an effective and general strategy for developing highly efficient and durable nonnoble electrocatalysts for catalyzing both hydrogen evolution reaction(HER)and oxy...Constructing heterointerface engineering has becoming an effective and general strategy for developing highly efficient and durable nonnoble electrocatalysts for catalyzing both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In this work,we synthesized a self-supporting heterogeneous NiSe@Co_(0.85)Se/NF electrocatalyst using a facile in situ selenization of transition metal precursors that coated on the nickel foam(NF)in polyol solution.The NF was used as both conductive substrate and nickel source,ensuring superior electronic conductivity for catalyzing.The NiSe@-Co_(0.85)Se/NF exhibited remarkable bifunctional electrocatalytic activities with HER overpotential of 168 mV and OER overpotential of 258 mV to achieve 10 mA·cm-2.The water splitting system using NiSe@Co_(0.85)Se/NF as both anode and cathode electrodes achieved a current density of 10 mA·cm^(-2) at 1.61 V with nearly 100% faradaic efficiency and impressively long-term stability.The efficient bifunctional catalytic performance of NiSe@-Co_(0.85)Se/NF should be attributed to the electronic modulation and synergistic effect between NiSe and Co_(0.85)Se,the intrinsic metallic conductivity and the enlarged active sites exposure.This work provides a facile method for developing heterogeneous bifunctional catalysts for advanced electrochemical energy conversion technologies.展开更多
Oxygen evolution reaction(OER)is a kinetically harsh four-electron anode reaction that requires a large overpotential to provide current and is of great importance in renewable electrochemical technique.Ir/Rubased per...Oxygen evolution reaction(OER)is a kinetically harsh four-electron anode reaction that requires a large overpotential to provide current and is of great importance in renewable electrochemical technique.Ir/Rubased perovskite oxides hold great significance for application as OER electrocatalysts,due to that their multimetal-oxide forms can reduce the use of noble metals,and their compositional tunability can modulate the electronic structure and optimize OER performance.However,high operating potentials and corrosive environments pose a serious challenge to the development of durable Ir-based and Ru-based perovskite electrocatalysts.Tremendous efforts have been dedicated to improving the Ir/Ru-based perovskite activity to enhance the efficiency;however,progress in improving the durability of Ir/Ru-based perovskite electrocatalysts has been rather limited.In this review,the recent research progress of Ir/Ru-based perovskites is reviewed from the perspective of heteroatom doping,structural modulation,and formation of heterostructures.The dissolution mechanism studies of Ir/Ru and experimental attempts to improve the durability of Ir/Ru-based perovskite electrocatalysts are discussed.Challenges and outlooks for further developing Ru-and Irbased perovskite oxygen electrocatalysts are also presented.展开更多
Single-atom catalysts(SACs)have been widely utilized in electrochemical nitrogen reduction reactions(NRR)due to their high atomic utilization and selectivity.Owing to the unique sp/sp^(2)co-hybridization,graphyne mate...Single-atom catalysts(SACs)have been widely utilized in electrochemical nitrogen reduction reactions(NRR)due to their high atomic utilization and selectivity.Owing to the unique sp/sp^(2)co-hybridization,graphyne materials can offer stable adsorption sites for single metal atoms.To investigate the influence of the sp/sp^(2)hybrid carbon ratio on the electrocatalytic NRR performance of graphyne,a high-throughput screening of 81 catalysts,with27 transition metals loaded on graphyne(GY1),graphdiyne(GY2),and graphtriyne(GY3),was conducted using firstprinciples calculations.The results of the screening revealed that Ti@GY3 exhibits the lowest energy barrier for the rate-determining step(0.32 eV)in NRR.Further,to explore the impact of different sp/sp^(2)-hybridized carbon ratios on the catalytic activity of SACs,the mechanism of nitrogen(N_(2))adsorption,activation,and the comprehensive pathway of NRR on Ti@GY1,Ti@GY2,and Ti@GY3 was systematically investigated.It was found that the ratio of sp/sp^(2)-hybridized carbon can significantly modulate the d-band center of the metal,thus affecting the energy barrier of the rate-determining step in NRR,decreasing from Ti@GY1(0.59 eV)to Ti@GY2(0.49 eV);and further to Ti@GY3(0.32 eV).Additionally,the Hall conductance was found to increase with the bias voltage in the range of 0.4-1 V,as calculated by Nanodcal software,demonstrating an improvement in the conductivity of the SAC.In summary,this work provides theoretical guidance for modulating the electrocatalytic nitrogen reduction activity of SACs by varying the ratio of sp/sp^(2)hybrid carbon,with Ti@GY3 showing potential as an excellent NRR catalyst.展开更多
Seawater battery is an advanced energy storage system that enables conversion of chemical energy to electricity by consuming metals,dissolved oxygen and seawater in anode,cathode and electrolyte,respectively.However,t...Seawater battery is an advanced energy storage system that enables conversion of chemical energy to electricity by consuming metals,dissolved oxygen and seawater in anode,cathode and electrolyte,respectively.However,the oxygen reduction reaction(ORR)activity and stability of electrocatalysts can be easily deactivated due to the severe Cl~-permeation and corrosion in seawater electrolyte.Herein,we developed a structural buffer engineering strategy by spontaneously anchoring Cl~-intoα-Co(OH)_(2) as efficient and stable ORR electrocatalysts,in which the ultrathinα-Co(OH)_(2) nanosheets were synthesized using an ultrafast solution high-temperature shock(SHTS)strategy.The large lattice space(~0.8 nm)of layeredα-Co(OH)_(2) ensured the spontaneously penetration of Cl~-into the lattice structure and replaced part of OH~-to formα-Co(OH)_(2-x)Cl_x.The continuous leaching and compensating of saturated Cl inα-Co(OH)_(2-x)Cl_x could enhance the Cl~-corrosion resistance and modulate electronic structure of Co metallic sites,thus improving the ORR electrocatalytic activity and stability in seawater electrolyte.Theα-Co(OH)_(2-x)Cl_x seawater batteries display superior onset and half-wave potentials of 0.71 and 0.66 V,respectively,which are much better than the counterparts ofα-Co(OH)_(2) and ofβ-Co(OH)_(2) with no Cl~-penetrating and no buffer structure.Theα-Co(OH)_(2-x)Cl_x-based seawater batteries display stable open-circuit potential of 1.69 V and outstanding specific capacity of 1345 mAh·g^(-1).展开更多
基金financially supported by the National Natural Science Foundation of China(No.51804216)。
文摘Constructing heterointerface engineering has becoming an effective and general strategy for developing highly efficient and durable nonnoble electrocatalysts for catalyzing both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In this work,we synthesized a self-supporting heterogeneous NiSe@Co_(0.85)Se/NF electrocatalyst using a facile in situ selenization of transition metal precursors that coated on the nickel foam(NF)in polyol solution.The NF was used as both conductive substrate and nickel source,ensuring superior electronic conductivity for catalyzing.The NiSe@-Co_(0.85)Se/NF exhibited remarkable bifunctional electrocatalytic activities with HER overpotential of 168 mV and OER overpotential of 258 mV to achieve 10 mA·cm-2.The water splitting system using NiSe@Co_(0.85)Se/NF as both anode and cathode electrodes achieved a current density of 10 mA·cm^(-2) at 1.61 V with nearly 100% faradaic efficiency and impressively long-term stability.The efficient bifunctional catalytic performance of NiSe@-Co_(0.85)Se/NF should be attributed to the electronic modulation and synergistic effect between NiSe and Co_(0.85)Se,the intrinsic metallic conductivity and the enlarged active sites exposure.This work provides a facile method for developing heterogeneous bifunctional catalysts for advanced electrochemical energy conversion technologies.
基金financially supported by the Key Research and Development Program of Hainan Province(No.ZDYF2022GXJS006)the National Natural Science Foundation of China(Nos.52231008,52201009 and 52001227)+2 种基金Hainan Provincial Natural Science Foundation of China(No.223RC401)the Education Department of Hainan Province(No.Hnky2023ZD-2)the Starting Research Funds of the Hainan University of China(Nos.KYQD(ZR)-21105 and XJ2300002951)。
文摘Oxygen evolution reaction(OER)is a kinetically harsh four-electron anode reaction that requires a large overpotential to provide current and is of great importance in renewable electrochemical technique.Ir/Rubased perovskite oxides hold great significance for application as OER electrocatalysts,due to that their multimetal-oxide forms can reduce the use of noble metals,and their compositional tunability can modulate the electronic structure and optimize OER performance.However,high operating potentials and corrosive environments pose a serious challenge to the development of durable Ir-based and Ru-based perovskite electrocatalysts.Tremendous efforts have been dedicated to improving the Ir/Ru-based perovskite activity to enhance the efficiency;however,progress in improving the durability of Ir/Ru-based perovskite electrocatalysts has been rather limited.In this review,the recent research progress of Ir/Ru-based perovskites is reviewed from the perspective of heteroatom doping,structural modulation,and formation of heterostructures.The dissolution mechanism studies of Ir/Ru and experimental attempts to improve the durability of Ir/Ru-based perovskite electrocatalysts are discussed.Challenges and outlooks for further developing Ru-and Irbased perovskite oxygen electrocatalysts are also presented.
基金financially supported by the National Natural Science Foundation of China(Nos.52301011,52231008,52142304,52177220,52101182 and U23A200767)Hainan Provincial Natural Science Foundation of China(No.524QN226)+2 种基金the Key research and development program of Hainan province(No.ZDYF2022GXJS006)the Starting Research Fund from the Hainan University(No.KYQD(ZR)23026)the International Science&Technology Cooperation Program of Hainan Province(No.GHYF2023007)。
文摘Single-atom catalysts(SACs)have been widely utilized in electrochemical nitrogen reduction reactions(NRR)due to their high atomic utilization and selectivity.Owing to the unique sp/sp^(2)co-hybridization,graphyne materials can offer stable adsorption sites for single metal atoms.To investigate the influence of the sp/sp^(2)hybrid carbon ratio on the electrocatalytic NRR performance of graphyne,a high-throughput screening of 81 catalysts,with27 transition metals loaded on graphyne(GY1),graphdiyne(GY2),and graphtriyne(GY3),was conducted using firstprinciples calculations.The results of the screening revealed that Ti@GY3 exhibits the lowest energy barrier for the rate-determining step(0.32 eV)in NRR.Further,to explore the impact of different sp/sp^(2)-hybridized carbon ratios on the catalytic activity of SACs,the mechanism of nitrogen(N_(2))adsorption,activation,and the comprehensive pathway of NRR on Ti@GY1,Ti@GY2,and Ti@GY3 was systematically investigated.It was found that the ratio of sp/sp^(2)-hybridized carbon can significantly modulate the d-band center of the metal,thus affecting the energy barrier of the rate-determining step in NRR,decreasing from Ti@GY1(0.59 eV)to Ti@GY2(0.49 eV);and further to Ti@GY3(0.32 eV).Additionally,the Hall conductance was found to increase with the bias voltage in the range of 0.4-1 V,as calculated by Nanodcal software,demonstrating an improvement in the conductivity of the SAC.In summary,this work provides theoretical guidance for modulating the electrocatalytic nitrogen reduction activity of SACs by varying the ratio of sp/sp^(2)hybrid carbon,with Ti@GY3 showing potential as an excellent NRR catalyst.
基金financially supported by the Key Research and Development Project of Hainan Province(No.ZDYF2022GXJS006)the National Natural Science Foundation of China(Nos.52177220 and 52231008)。
文摘Seawater battery is an advanced energy storage system that enables conversion of chemical energy to electricity by consuming metals,dissolved oxygen and seawater in anode,cathode and electrolyte,respectively.However,the oxygen reduction reaction(ORR)activity and stability of electrocatalysts can be easily deactivated due to the severe Cl~-permeation and corrosion in seawater electrolyte.Herein,we developed a structural buffer engineering strategy by spontaneously anchoring Cl~-intoα-Co(OH)_(2) as efficient and stable ORR electrocatalysts,in which the ultrathinα-Co(OH)_(2) nanosheets were synthesized using an ultrafast solution high-temperature shock(SHTS)strategy.The large lattice space(~0.8 nm)of layeredα-Co(OH)_(2) ensured the spontaneously penetration of Cl~-into the lattice structure and replaced part of OH~-to formα-Co(OH)_(2-x)Cl_x.The continuous leaching and compensating of saturated Cl inα-Co(OH)_(2-x)Cl_x could enhance the Cl~-corrosion resistance and modulate electronic structure of Co metallic sites,thus improving the ORR electrocatalytic activity and stability in seawater electrolyte.Theα-Co(OH)_(2-x)Cl_x seawater batteries display superior onset and half-wave potentials of 0.71 and 0.66 V,respectively,which are much better than the counterparts ofα-Co(OH)_(2) and ofβ-Co(OH)_(2) with no Cl~-penetrating and no buffer structure.Theα-Co(OH)_(2-x)Cl_x-based seawater batteries display stable open-circuit potential of 1.69 V and outstanding specific capacity of 1345 mAh·g^(-1).
