The cyclic voltammetry, open current potential-time curve after potentiostatic electrolysis, the currenttime curve at potential step, XRD, EDAX and EPMA were used to study the electrode process of Ho3+ reduction on n...The cyclic voltammetry, open current potential-time curve after potentiostatic electrolysis, the currenttime curve at potential step, XRD, EDAX and EPMA were used to study the electrode process of Ho3+ reduction on nickel electrode in molten KCI-HoC13 and the phases of surface alloy layer. The Ho-Ni alloys were deposited when Hos+ was reduced on the nickel electrode. The free energies of formation for the intermetallic compounds between Ho and Ni, the diffusion coefficients and diffusion activation energy of Ho astom in the alloy phase were determined.展开更多
It is generally considered that the hydrogenation of CO2 is the critical bottleneck of the CO2 electroreduction.In this work,with the aid of density functional theory(DFT)calculations,the catalytic hydrogenation of CO...It is generally considered that the hydrogenation of CO2 is the critical bottleneck of the CO2 electroreduction.In this work,with the aid of density functional theory(DFT)calculations,the catalytic hydrogenation of CO2 molecules over Indium-doped SnP3 catalyst were systematically studied.Through doping with indium(In)atom,the energy barrier of CO2 protonation is reduced and OCHO*species could easily be generated.This is mainly due to the p orbital of In exhibits strong hybridization with the p orbital of O,indicating that there is a strong interaction between OCHO*and In-doped SnP3 catalyst.As a result,In-doped SnP3 possesses high-efficiency and high-selectivity for converting CO2 into HCOOH with a low limiting potential of-0.17 V.Our findings will offer theoretical guidance to CO2 electroreduction.展开更多
Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the H...Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the Haber-Bosch process and electrochemical nitrogen reduction reaction.Therefore,it represents a promising approach to safeguard the ecological environment by enabling the cycling of nitrogen species.This review begins by discussing the theoretical insights of the NO_(3)RR.It then summarizes recent advances in catalyst design and construction strategies,including alloying,structure engineering,surface engineering,and heterostructure engineering.Finally,the challenges and prospects in this field are presented.This review aims to guide for enhancing the efficiency of electrocatalysts in the NO_(3)RR,and offers insights for converting NO_(3)-to NH_(3).展开更多
Electrocatalytic CO_(2)reduction into CO has been regarded as one of the most promising strategies for sustainable carbon cycles at ambient conditions,but still faces challenges to achieve both high product selectivit...Electrocatalytic CO_(2)reduction into CO has been regarded as one of the most promising strategies for sustainable carbon cycles at ambient conditions,but still faces challenges to achieve both high product selectivity and large current density.Here,we report a Ni_(4)N/Ni_(3)ZnC_(0.7)heterostructured electrocatalyst embedded in accordion-like N-doped carbon through a simple molten salt annealing strategy.The optimal Ni_(4)N/Ni_(3)ZnC_(0.7)electrocatalyst achieves a high CO Faraday efficiency of 92.3%and a large total current density of-15.8 m A cm^(-2)at-0.8 V versus reversible hydrogen electrode,together with a long-term stability about 30 h.Density functional theory results reveal that the energy barrier for*COOH intermediate formation largely decreased on Ni_(4)N/Ni_(3)ZnC_(0.7)heterostructure compared with Ni_(4)N and Ni_(3)ZnC_(0.7),thus giving rise to enhanced activity and selectivity.A rechargeable Zn-CO_(2)battery is further assembled with Ni_(4)N/Ni_(3)ZnC_(0.7)catalyst as the cathode,which shows a maximum power density of 0.85 mW cm^(-2)and excellent stability.展开更多
The cyclic voltammetry,electrode potential-time curve after potentiostatic electrolysis,potential-step method and X-ray diffraction were used to study the electrochemical reaction of Dy￣(3+) in equimolar NaCl-KCl mix...The cyclic voltammetry,electrode potential-time curve after potentiostatic electrolysis,potential-step method and X-ray diffraction were used to study the electrochemical reaction of Dy￣(3+) in equimolar NaCl-KCl mixture on Ni electrode.The DyNi5 forms at first and then the intermetallic compounds of Dy-Ni containing more Dy form in sequence.The metallic Dy deposits at last.The Dy-Ni alloy was prepared by consumable cathode in molten chlorides.The Dy-Ni alloy contained Dy over 85 wt% was obtained.The composition of alloy was DyNi5 and Dy.The current efficiency and the recovery of Dy were near 80%.展开更多
基金the National Natural Science Foundation of China!2890179
文摘The cyclic voltammetry, open current potential-time curve after potentiostatic electrolysis, the currenttime curve at potential step, XRD, EDAX and EPMA were used to study the electrode process of Ho3+ reduction on nickel electrode in molten KCI-HoC13 and the phases of surface alloy layer. The Ho-Ni alloys were deposited when Hos+ was reduced on the nickel electrode. The free energies of formation for the intermetallic compounds between Ho and Ni, the diffusion coefficients and diffusion activation energy of Ho astom in the alloy phase were determined.
基金supported by Guizhou Provincial Science and Technology Foundation,China(No.[2019]1229)the National Natural Science Foundation of China(Nos.21361007,51776046)。
文摘通过高温固相技术合成Ho^(3+)和Yb^(3+)共掺杂La_(7)P_(3)O_(18)上转换荧光粉。XRD结果表明,合成样品是空间群为P21/n的单斜结构的La_(7)P_(3)O_(18)晶体和少量La PO4晶体的混合物。紫外可见漫反射光谱结果证实La_(7)P_(3)O_(18)晶体是一种光学带隙为4.10 e V的间接半导体。经980 nm激光激发,Ho^(3+)和Yb^(3+)共掺杂La_(7)P_(3)O_(18)荧光粉发射出Ho^(3+)离子特征的蓝色(486 nm)、绿色(550 nm)和红色(661 nm)特征峰,其中,661 nm处发射峰在样品上转换发光光谱中占主导地位。此外,随着Ho^(3+)和Yb^(3+)掺杂量的增加,样品上转换发光强度先增大后减小。当Ho^(3+)和Yb^(3+)的掺杂量分别达到1%和10%(摩尔分数)时,样品出现浓度猝灭现象,其机制为电四极-电四极相互作用。泵浦功率和发光强度关系表明,样品的绿光和红光发射均源于双光子吸收过程激发。Ho^(3+)和Yb^(3+)共掺杂La_(7)P_(3)O_(18)晶体上转换发光色坐标位于橙红色区域。
基金supported by the National Natural Science Foundation of China(Nos.11675051,51302079,51702138)the Natural Science Foundation of Hunan Province(No.2017JJ1008)the Key Research and Development Program of Hunan Province of China(No.2018GK2031)。
文摘It is generally considered that the hydrogenation of CO2 is the critical bottleneck of the CO2 electroreduction.In this work,with the aid of density functional theory(DFT)calculations,the catalytic hydrogenation of CO2 molecules over Indium-doped SnP3 catalyst were systematically studied.Through doping with indium(In)atom,the energy barrier of CO2 protonation is reduced and OCHO*species could easily be generated.This is mainly due to the p orbital of In exhibits strong hybridization with the p orbital of O,indicating that there is a strong interaction between OCHO*and In-doped SnP3 catalyst.As a result,In-doped SnP3 possesses high-efficiency and high-selectivity for converting CO2 into HCOOH with a low limiting potential of-0.17 V.Our findings will offer theoretical guidance to CO2 electroreduction.
基金supported by the National Natural Science Foundation of China(22202151)Fundamental Research Program of Shanxi Province(202203021212243)。
文摘Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the Haber-Bosch process and electrochemical nitrogen reduction reaction.Therefore,it represents a promising approach to safeguard the ecological environment by enabling the cycling of nitrogen species.This review begins by discussing the theoretical insights of the NO_(3)RR.It then summarizes recent advances in catalyst design and construction strategies,including alloying,structure engineering,surface engineering,and heterostructure engineering.Finally,the challenges and prospects in this field are presented.This review aims to guide for enhancing the efficiency of electrocatalysts in the NO_(3)RR,and offers insights for converting NO_(3)-to NH_(3).
基金financially supported by the National Key Research and Development Program,China(2018YFB1502503)the 2021 Talent Introduction Project of Chongqing Medical and Pharmaceutical College(ygz2021104)。
文摘Electrocatalytic CO_(2)reduction into CO has been regarded as one of the most promising strategies for sustainable carbon cycles at ambient conditions,but still faces challenges to achieve both high product selectivity and large current density.Here,we report a Ni_(4)N/Ni_(3)ZnC_(0.7)heterostructured electrocatalyst embedded in accordion-like N-doped carbon through a simple molten salt annealing strategy.The optimal Ni_(4)N/Ni_(3)ZnC_(0.7)electrocatalyst achieves a high CO Faraday efficiency of 92.3%and a large total current density of-15.8 m A cm^(-2)at-0.8 V versus reversible hydrogen electrode,together with a long-term stability about 30 h.Density functional theory results reveal that the energy barrier for*COOH intermediate formation largely decreased on Ni_(4)N/Ni_(3)ZnC_(0.7)heterostructure compared with Ni_(4)N and Ni_(3)ZnC_(0.7),thus giving rise to enhanced activity and selectivity.A rechargeable Zn-CO_(2)battery is further assembled with Ni_(4)N/Ni_(3)ZnC_(0.7)catalyst as the cathode,which shows a maximum power density of 0.85 mW cm^(-2)and excellent stability.
文摘The cyclic voltammetry,electrode potential-time curve after potentiostatic electrolysis,potential-step method and X-ray diffraction were used to study the electrochemical reaction of Dy￣(3+) in equimolar NaCl-KCl mixture on Ni electrode.The DyNi5 forms at first and then the intermetallic compounds of Dy-Ni containing more Dy form in sequence.The metallic Dy deposits at last.The Dy-Ni alloy was prepared by consumable cathode in molten chlorides.The Dy-Ni alloy contained Dy over 85 wt% was obtained.The composition of alloy was DyNi5 and Dy.The current efficiency and the recovery of Dy were near 80%.
