In recent years,extensiveresearch and development have been conducted on renewable energies to overcome the problems caused by fossil fuel consumption.In the meantime,the production of hydrogen energy through electroc...In recent years,extensiveresearch and development have been conducted on renewable energies to overcome the problems caused by fossil fuel consumption.In the meantime,the production of hydrogen energy through electrochemical water spltting(EWS)has been limited by various challenges,such as high required overpotential.Additionally,other methods of hydrogen production may lead to environmental problems,such as greenhouse gas emissions.Effective electrocatalysts can significantly mitigate the EWS challenges.Oxy-hydroxide compoundspossess unique properties that make them effective electrocatalysts for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Additionally,the utilizationof the electrodeposition method,a binder-free technique,enables the production of electrodes exhibiting favorable electrocatalytic activity and stability.This review article provides an overview of the challenges associated with the EWS technique,highlighting the importance of transition metal oxy-hydroxide electrodes in facilitating the HER and OER reactions.Additionally,the paper evaluates the effectiveness of fabricated transition metal oxy-hydroxide electrodes through electrodeposition and suggests potential areas for future research on Ews.展开更多
The sluggish kinetics of the oxygen evolution reaction(OER)severely limits the efficiency of electrochemical water splitting for sustainable hydrogen production.Developing cost-effective and efficient OER electrocatal...The sluggish kinetics of the oxygen evolution reaction(OER)severely limits the efficiency of electrochemical water splitting for sustainable hydrogen production.Developing cost-effective and efficient OER electrocatalysts based on earth-abundant elements is thus highly desirable.Herein,we report a nanoporous(CoNiFe)OOH electrocatalyst decorated with Zn(OH)_(4)^(2−)anions,synthesized via electrochemical surface reconstruction of ZnO-decorated CoNiFe medium-entropy alloys(MEAs).The reconstructed(CoNiFe)OOH adsorbed with Zn(OH)_(4)^(2−)anions serves as the real active phase,featuring abundant catalytic sites and enhanced OH−accessibility.Adsorbed Zn(OH)_(4)^(2−)anions promote OH−transfer and facilitate electron redistribution at the active sites,particularly enhancing Co site activity,as revealed by density functional theory(DFT)calculations.As a result,the optimized CoNiFeZn@NF-EO electrode exhibits outstanding OER performance,achieving a low overpotential of 264 mV at 10 mA·cm^(−2),a Tafel slope of 46.6 mV·dec^(−1),and remarkable long-term stability in alkaline electrolyte.This work provides new insights into the synergistic effect between surface reconstruction and Zn-based species,offering a promising strategy for designing high-performance OER electrocatalysts.展开更多
基金This research was funded by Iran National Science Foundation(INSF)under project(No.4024998).
文摘In recent years,extensiveresearch and development have been conducted on renewable energies to overcome the problems caused by fossil fuel consumption.In the meantime,the production of hydrogen energy through electrochemical water spltting(EWS)has been limited by various challenges,such as high required overpotential.Additionally,other methods of hydrogen production may lead to environmental problems,such as greenhouse gas emissions.Effective electrocatalysts can significantly mitigate the EWS challenges.Oxy-hydroxide compoundspossess unique properties that make them effective electrocatalysts for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Additionally,the utilizationof the electrodeposition method,a binder-free technique,enables the production of electrodes exhibiting favorable electrocatalytic activity and stability.This review article provides an overview of the challenges associated with the EWS technique,highlighting the importance of transition metal oxy-hydroxide electrodes in facilitating the HER and OER reactions.Additionally,the paper evaluates the effectiveness of fabricated transition metal oxy-hydroxide electrodes through electrodeposition and suggests potential areas for future research on Ews.
基金supported by the National Natural Science Foundation of China(Nos.52202093 and 52304325)the Natural Science Research of Jiangsu Higher Education Institutions of China(No.22KJB430021)Jiangsu Provincial Double Innovation Doctor Program(No.JSSCBS20221258).
文摘The sluggish kinetics of the oxygen evolution reaction(OER)severely limits the efficiency of electrochemical water splitting for sustainable hydrogen production.Developing cost-effective and efficient OER electrocatalysts based on earth-abundant elements is thus highly desirable.Herein,we report a nanoporous(CoNiFe)OOH electrocatalyst decorated with Zn(OH)_(4)^(2−)anions,synthesized via electrochemical surface reconstruction of ZnO-decorated CoNiFe medium-entropy alloys(MEAs).The reconstructed(CoNiFe)OOH adsorbed with Zn(OH)_(4)^(2−)anions serves as the real active phase,featuring abundant catalytic sites and enhanced OH−accessibility.Adsorbed Zn(OH)_(4)^(2−)anions promote OH−transfer and facilitate electron redistribution at the active sites,particularly enhancing Co site activity,as revealed by density functional theory(DFT)calculations.As a result,the optimized CoNiFeZn@NF-EO electrode exhibits outstanding OER performance,achieving a low overpotential of 264 mV at 10 mA·cm^(−2),a Tafel slope of 46.6 mV·dec^(−1),and remarkable long-term stability in alkaline electrolyte.This work provides new insights into the synergistic effect between surface reconstruction and Zn-based species,offering a promising strategy for designing high-performance OER electrocatalysts.
