It is essential to design and synthesize non-noble metal-based electrocatalysts for the highly efficient hydrogen evolution reaction(HER).In this study,we have successfully prepared a self-supporting phosphide heteros...It is essential to design and synthesize non-noble metal-based electrocatalysts for the highly efficient hydrogen evolution reaction(HER).In this study,we have successfully prepared a self-supporting phosphide heterostructured electrocatalyst,where CoMoP_(2) nanosheets are well distributed on the surface of Co_(2)P hollow nanobricks on Ni foam.The testing results demonstrated that the as-prepared Co_(2)P/CoMoP_(2) exhibited excellent HER performance with an overpotential of 36 mV and 43 mV(at 10 mA cm^(-2))in alkaline water and seawater electrolyte,respectively.Meanwhile,it also showed good oxygen evolution reaction(OER)activity at 10 mA cm^(-2) with an overpotential of 254 mV in alkaline water and 268 mV in alkaline seawater electrolyte,respectively.Theoretical research studies have verified that the activation energy barrier of H_(2)O on the surface of CoMoP_(2) was 0.63 eV,while that on the surface of Co_(2)P was 0.73 eV,indicating that CoMoP_(2) can promote the Volmer step.Also,the electronic redistribution at the interface enabled the Co_(2)P/CoMoP_(2) heterojunction to achieve the ideal Gibbs free energy of hydrogen adsorption(0.16 eV).Interface engineering provides a simple and efficient approach for designing highly efficient Co_(2)P-based electrocatalysts.展开更多
We report a very convenient and cost-effective approach for the fabrication of a self-supported Co@CoTe_(2)electrode comprising CoTe_(2)nanoparticles used for water oxidation catalysis,which is achieved by one-step hy...We report a very convenient and cost-effective approach for the fabrication of a self-supported Co@CoTe_(2)electrode comprising CoTe_(2)nanoparticles used for water oxidation catalysis,which is achieved by one-step hydrothermal treatment of commercially available cobalt foam.The characteristics of the as-fabricated Co@CoTe_(2)electrode in terms of the crystal structure,surface morphology and chemical components were analyzed.Moreover,the electrochemical properties of the Co@CoTe_(2)electrocatalyst used for water electrolysis were comprehensively investigated.When used to catalyze the oxygen evolution reaction(OER)in 1.0 M KOH,Co@CoTe_(2)electrodes exhibit outstanding catalytic activity and long-term durability,thus outperforming many well-studied cobalt based dichalcogenides(including tellurides,selenides and sulfides)that have been recently reported in the literature.Particularly,Co@CoTe_(2)prepared at 240℃(Co@CoTe_(2)-240)requires a low overpotential of only 286 mV to attain an anodic current density of 10 mA cm^(−2)and shows fast kinetics for the OER with a small Tafel slope of 42 mV dec^(−1).Moreover,the overpotential needed to maintain 10 mA cm^(−2)is merely increased by 20 mV after continuous OER electrolysis for 16 hours,exhibiting excellent long-term stability.Given the commercial availability of porous Co foam,the convenient and scalable approach of hydrothermal synthesis and the outstanding catalytic performance,the self-supported Co@CoTe_(2)electrode reported here holds great promise as an important OER electrocatalyst in water splitting devices and metal–air batteries.展开更多
NiFe-based non-precious-metal catalysts are promising substitutes for noble-metal-based catalysts due to their outstanding electrochemical performance and endurance.Herein,a NiFe-based MOF supported on Ni foam was des...NiFe-based non-precious-metal catalysts are promising substitutes for noble-metal-based catalysts due to their outstanding electrochemical performance and endurance.Herein,a NiFe-based MOF supported on Ni foam was designed to obtain good OER and HER activities in alkaline media.Thanks to the 3-D hierarchical layer structure distributed on Ni foam,the high exposure of active sites,and the good conductance,as-obtained NiFe-MOF-5 presented advantages for its use in electrochemical catalysis.As a result,an overpotential of 168 mV at 10 mA cm^(−2)for the OER was reached.Moreover,the catalyst only required a cell voltage of 1.57 V at 10 mA cm^(−2)for overall water splitting,and it outperformed most previously reported non-precious-metal electrocatalysts in 1 M KOH.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.:22002146)Taishan Scholars Foundation of Shandong Province(no.:tsqn201909058).
文摘It is essential to design and synthesize non-noble metal-based electrocatalysts for the highly efficient hydrogen evolution reaction(HER).In this study,we have successfully prepared a self-supporting phosphide heterostructured electrocatalyst,where CoMoP_(2) nanosheets are well distributed on the surface of Co_(2)P hollow nanobricks on Ni foam.The testing results demonstrated that the as-prepared Co_(2)P/CoMoP_(2) exhibited excellent HER performance with an overpotential of 36 mV and 43 mV(at 10 mA cm^(-2))in alkaline water and seawater electrolyte,respectively.Meanwhile,it also showed good oxygen evolution reaction(OER)activity at 10 mA cm^(-2) with an overpotential of 254 mV in alkaline water and 268 mV in alkaline seawater electrolyte,respectively.Theoretical research studies have verified that the activation energy barrier of H_(2)O on the surface of CoMoP_(2) was 0.63 eV,while that on the surface of Co_(2)P was 0.73 eV,indicating that CoMoP_(2) can promote the Volmer step.Also,the electronic redistribution at the interface enabled the Co_(2)P/CoMoP_(2) heterojunction to achieve the ideal Gibbs free energy of hydrogen adsorption(0.16 eV).Interface engineering provides a simple and efficient approach for designing highly efficient Co_(2)P-based electrocatalysts.
基金financial support by the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2019WNLOKF018)the National Key Research and Development Program(No.2017YFE0192600)the Independent Innovation Foundation of Wuhan University of Technology(No.205201042)for the financial support for this research.
文摘We report a very convenient and cost-effective approach for the fabrication of a self-supported Co@CoTe_(2)electrode comprising CoTe_(2)nanoparticles used for water oxidation catalysis,which is achieved by one-step hydrothermal treatment of commercially available cobalt foam.The characteristics of the as-fabricated Co@CoTe_(2)electrode in terms of the crystal structure,surface morphology and chemical components were analyzed.Moreover,the electrochemical properties of the Co@CoTe_(2)electrocatalyst used for water electrolysis were comprehensively investigated.When used to catalyze the oxygen evolution reaction(OER)in 1.0 M KOH,Co@CoTe_(2)electrodes exhibit outstanding catalytic activity and long-term durability,thus outperforming many well-studied cobalt based dichalcogenides(including tellurides,selenides and sulfides)that have been recently reported in the literature.Particularly,Co@CoTe_(2)prepared at 240℃(Co@CoTe_(2)-240)requires a low overpotential of only 286 mV to attain an anodic current density of 10 mA cm^(−2)and shows fast kinetics for the OER with a small Tafel slope of 42 mV dec^(−1).Moreover,the overpotential needed to maintain 10 mA cm^(−2)is merely increased by 20 mV after continuous OER electrolysis for 16 hours,exhibiting excellent long-term stability.Given the commercial availability of porous Co foam,the convenient and scalable approach of hydrothermal synthesis and the outstanding catalytic performance,the self-supported Co@CoTe_(2)electrode reported here holds great promise as an important OER electrocatalyst in water splitting devices and metal–air batteries.
基金supported by the China Postdoctoral Science Foundation(2017M612496).
文摘NiFe-based non-precious-metal catalysts are promising substitutes for noble-metal-based catalysts due to their outstanding electrochemical performance and endurance.Herein,a NiFe-based MOF supported on Ni foam was designed to obtain good OER and HER activities in alkaline media.Thanks to the 3-D hierarchical layer structure distributed on Ni foam,the high exposure of active sites,and the good conductance,as-obtained NiFe-MOF-5 presented advantages for its use in electrochemical catalysis.As a result,an overpotential of 168 mV at 10 mA cm^(−2)for the OER was reached.Moreover,the catalyst only required a cell voltage of 1.57 V at 10 mA cm^(−2)for overall water splitting,and it outperformed most previously reported non-precious-metal electrocatalysts in 1 M KOH.
