Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directl...Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directly synthesized.The underlying structural reason for this phenomenon remains controversial.In this work,CoOOH and Co(OH)2with similar morphology are employed as model catalysts to investigate the origin of in-situ converted catalyst s high activity,as Co(OH)2can be fully converted to CoOOH during OER.In-situ Raman,electron paramagnetic resonance,HR-TEM,and X-ray spectroscopic studies reveal that O vacancies in the CoOOH converted from Co(OH)2play a key role in its higher intrinsic activity towards OER than directly synthesized CoOOH.Furthermore,theoretical calculations and electrochemical methods indicate that O vacancies in CoOOH affect the interaction between Co-O bond,downshift the d-band center of Co,further weaken the adsorption of OH*,and finally facilitate the OER process over CoOOH.This work not only provides a deep understanding of pre-catalyst's high OER activity by taking Co(OH)2as an example but also deliver insights into the activation process of other electrochemic al oxidation reactions.展开更多
Transition metal(TM)basic salts have been recognized as high-efficiency catalysts for electrocatalytic oxygen evolution reaction(OER),which is of great importance for producing clean hydrogen energy.Herein,novel OER e...Transition metal(TM)basic salts have been recognized as high-efficiency catalysts for electrocatalytic oxygen evolution reaction(OER),which is of great importance for producing clean hydrogen energy.Herein,novel OER electrocatalyst consisting of iron oxyhydroxide/nickel sulfate hydroxide nanobelts loaded on nickel foam(FeOOH/NiSH/NF)is reported,synthesized via a facile solvothermal-hydrolysis method.Impressively,the optimized FeOOH/NiSH/NF catalyst exhibits outstanding performance,requiring only a low overpotential of 265 mV to drive a current density of 50 mA·cm^(-2)for OER in alkaline media.Structure evolution of the catalysts under the OER process has been investigated through multiple characterization methods,and SO_(4)^(2-)adsorbed FeOOH/NiOOH is demonstrated to be the true active species.The essential role of incorporated FeOOH has been further elucidated by using density functional theory(DFT)calculations.This work not only reports a novel NiSH-based catalyst towards OER,but also provides insights for understanding the structure-property of TM basic saltbased hybrid OER catalysts.展开更多
基金financially supported by the financial support from Natural Science Foundation of China(No.22209129)the High-Level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(No.QCYRCXM-2022-123)+3 种基金the Innovation Capability Support Program of Shaanxi(No.2023-CXTD-26)the financial support from the"Young Talent Support Plan''of Xi'an Jiaotong University(No.HG6J024)the financial support from China Postdoctoral Science Foundation 2024M752560Postdoctoral Fellowship Program of CPSF under Grant Number GZB20230574
文摘Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directly synthesized.The underlying structural reason for this phenomenon remains controversial.In this work,CoOOH and Co(OH)2with similar morphology are employed as model catalysts to investigate the origin of in-situ converted catalyst s high activity,as Co(OH)2can be fully converted to CoOOH during OER.In-situ Raman,electron paramagnetic resonance,HR-TEM,and X-ray spectroscopic studies reveal that O vacancies in the CoOOH converted from Co(OH)2play a key role in its higher intrinsic activity towards OER than directly synthesized CoOOH.Furthermore,theoretical calculations and electrochemical methods indicate that O vacancies in CoOOH affect the interaction between Co-O bond,downshift the d-band center of Co,further weaken the adsorption of OH*,and finally facilitate the OER process over CoOOH.This work not only provides a deep understanding of pre-catalyst's high OER activity by taking Co(OH)2as an example but also deliver insights into the activation process of other electrochemic al oxidation reactions.
基金financially supported by the National Key R&D Program of China(No.2022YFA1504800)the National Natural Science Foundation of China(Nos.22202003 and 22209129)+2 种基金the High-Level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(No.QCYRCXM-2022-123)the Innovation Capability Support Program of Shaanxi(No.2023-CX-TD-26)the"Young Talent Support Plan"of Xi'an Jiaotong University(No.HG6J024)。
文摘Transition metal(TM)basic salts have been recognized as high-efficiency catalysts for electrocatalytic oxygen evolution reaction(OER),which is of great importance for producing clean hydrogen energy.Herein,novel OER electrocatalyst consisting of iron oxyhydroxide/nickel sulfate hydroxide nanobelts loaded on nickel foam(FeOOH/NiSH/NF)is reported,synthesized via a facile solvothermal-hydrolysis method.Impressively,the optimized FeOOH/NiSH/NF catalyst exhibits outstanding performance,requiring only a low overpotential of 265 mV to drive a current density of 50 mA·cm^(-2)for OER in alkaline media.Structure evolution of the catalysts under the OER process has been investigated through multiple characterization methods,and SO_(4)^(2-)adsorbed FeOOH/NiOOH is demonstrated to be the true active species.The essential role of incorporated FeOOH has been further elucidated by using density functional theory(DFT)calculations.This work not only reports a novel NiSH-based catalyst towards OER,but also provides insights for understanding the structure-property of TM basic saltbased hybrid OER catalysts.
