It is highly desirable but still a challenging task to find a simple,fast and straightforward method to greatly improve the alkaline oxygen evolution reaction(OER)performance of a NiCo_(2)O_(4)catalyst.In this communi...It is highly desirable but still a challenging task to find a simple,fast and straightforward method to greatly improve the alkaline oxygen evolution reaction(OER)performance of a NiCo_(2)O_(4)catalyst.In this communication,we demonstrate that developing an amorphous borate shell on a NiCo_(2)O_(4)surface can boost its OER activity in alkaline media.As a 3D catalyst electrode,a NiCo_(2)O_(4)@Ni–Co–B nanoarray on carbon cloth needs an overpotential of only 270 mV to achieve a geometrical catalytic current density of 10 mA cm^(−2)in 1.0 M KOH,which is 100 mV less than that for a NiCo_(2)O_(4)nanoarray.Notably,this electrode also demonstrates strong electrochemical durability,maintaining its activity for at least 100 h.The superior activity of NiCo_(2)O_(4)@Ni–Co–B is attributed to the amorphous Ni–Co–B shell on NiCo_(2)O_(4)favoring the in situ electrochemical generation of more active species during water oxidation.展开更多
In the pursuit of advancing electrocatalysts for the alkaline oxygen evolution reaction(OER),the development of nickel-based metal-organic frameworks(MOFs)with a judicious balance of cost-effectiveness and catalytic e...In the pursuit of advancing electrocatalysts for the alkaline oxygen evolution reaction(OER),the development of nickel-based metal-organic frameworks(MOFs)with a judicious balance of cost-effectiveness and catalytic efficacy is of paramount importance.Herein,we have achieved a commendable feat in the synthesis of Ni MOFs integrated with uniformly dispersed Fe and S species on a FeS substrate based on the precipitation-dissolution equilibrium.For the obtained Ni MOFs/FeS/IF catalyst,three factors including excellent conductivity of FeS substrate,conjugated carboxylate ligands and spindle-shaped structure with uniformly dispersed Fe and S can contribute to the enhanced activity for OER.The electrochemical measurements show that Ni MOFs/FeS/IF requires overpotentials of 250 and 280 mV to reach current densities of 100 mA cm^(-2) in 1 M KOH and 1 M KOH seawater,respectively,as compared to that(427@100 mA cm^(-2) in 1 M KOH,455@100 mA cm^(-2) in 1 M KOH seawater)of Ni MOFs/NF.Interestingly,the Ni MOFs/FeS/IF electrode displayed remarkable electrochemical stability with a high current density of 500 mA cm^(-2) after testing for 50 h,which is attributed to the synergistic effect of the bimetallic centers and optimized coordination environments via Ni-S bonds.The study reveals the potential for efficiently driving freshwater and seawater splitting by uniformly distributing anions and cations based on the precipitation-dissolution equilibrium during the in situ generation of metal-organic frameworks toward advanced electrocatalysts.展开更多
基金supported by the National Natural Science Foundation of China(No.21575137 and 21375076).
文摘It is highly desirable but still a challenging task to find a simple,fast and straightforward method to greatly improve the alkaline oxygen evolution reaction(OER)performance of a NiCo_(2)O_(4)catalyst.In this communication,we demonstrate that developing an amorphous borate shell on a NiCo_(2)O_(4)surface can boost its OER activity in alkaline media.As a 3D catalyst electrode,a NiCo_(2)O_(4)@Ni–Co–B nanoarray on carbon cloth needs an overpotential of only 270 mV to achieve a geometrical catalytic current density of 10 mA cm^(−2)in 1.0 M KOH,which is 100 mV less than that for a NiCo_(2)O_(4)nanoarray.Notably,this electrode also demonstrates strong electrochemical durability,maintaining its activity for at least 100 h.The superior activity of NiCo_(2)O_(4)@Ni–Co–B is attributed to the amorphous Ni–Co–B shell on NiCo_(2)O_(4)favoring the in situ electrochemical generation of more active species during water oxidation.
基金financially supported by National Natural Science Foundation of China(52174283 and 52274308).
文摘In the pursuit of advancing electrocatalysts for the alkaline oxygen evolution reaction(OER),the development of nickel-based metal-organic frameworks(MOFs)with a judicious balance of cost-effectiveness and catalytic efficacy is of paramount importance.Herein,we have achieved a commendable feat in the synthesis of Ni MOFs integrated with uniformly dispersed Fe and S species on a FeS substrate based on the precipitation-dissolution equilibrium.For the obtained Ni MOFs/FeS/IF catalyst,three factors including excellent conductivity of FeS substrate,conjugated carboxylate ligands and spindle-shaped structure with uniformly dispersed Fe and S can contribute to the enhanced activity for OER.The electrochemical measurements show that Ni MOFs/FeS/IF requires overpotentials of 250 and 280 mV to reach current densities of 100 mA cm^(-2) in 1 M KOH and 1 M KOH seawater,respectively,as compared to that(427@100 mA cm^(-2) in 1 M KOH,455@100 mA cm^(-2) in 1 M KOH seawater)of Ni MOFs/NF.Interestingly,the Ni MOFs/FeS/IF electrode displayed remarkable electrochemical stability with a high current density of 500 mA cm^(-2) after testing for 50 h,which is attributed to the synergistic effect of the bimetallic centers and optimized coordination environments via Ni-S bonds.The study reveals the potential for efficiently driving freshwater and seawater splitting by uniformly distributing anions and cations based on the precipitation-dissolution equilibrium during the in situ generation of metal-organic frameworks toward advanced electrocatalysts.
