纳米片状CuCo_(2)O_(4)的合成及析氧性能研究

Synthesis of CuCo_(2)O_(4)nanoflakes for oxygen evolution reaction

调控催化剂形貌和结构,优化表面特性,是提高催化性能的重要策略.通过水热合成铜钴双氢氧化物(CuCo LDH)前驱体,再经高温热解制得交叉连接片状CuCo_(2)O_(4)催化剂.该催化剂的粗糙表面和片层间隙有利于电解质的充分扩散吸附;其表面O缺陷能调节相邻金属位点价态,并能提高导电性,适合用于电化学催化.优化元素组成所制备CuCo_(2)O_(4)-1具有良好碱性析氧反应(OER)催化活性,在1 mol·L^(-1)KOH电解质中,电流密度为100 mA·cm^(-2)时的过电位(η)为362 mV,OER塔菲尔斜率为112.2 mV·dec^(-1),经过50 h的计时电位测试,η保持稳定,也显示出良好催化稳定性。为碱性OER电催化剂的设计提供了可行方案.

The manipulation of morphology and structure,as well as the optimization of surface characteristics of catalyst are significant tacticses to enhance the catalytic performance.In this work,CuCo_(2)O_(4)catalyst with cross connected nanoflakes structure was prepared by one-step hydrothermal synthesis of copper cobalt bimetallic hydroxide precursor(CuCo LDH)followed by high temperature pyrolysis treatment.The rough surface and the inter-flake voids within the as-prepared catalyst facilitate the sufficient diffusion and adsorption of electrolyte,meanwhile,the superficial O vacancies can regulate the valences of adjacent metal sites and increase the conductivity,these surface features are conducive to electrocatalytic feature.The typical CuCo_(2)O_(4)-1 with optimal elemental composition owns good catalytic activity for alkali oxygen evolution reaction(OER).In 1 mol·L^(-1)KOH electrolyte,the overpotential(η)achieved at 362 mV to arise response current density of 100 mA·cm^(-2),and demonstrated Tafel slope of 112.2 mV·dec^(-1).In addition,theηmaintained unvaried upon 50 h of chronopotentiometry test,showing the fine catalytic stability.The current work provides a feasible solution to design efficient catalyst for alkali OER.