低电负性阴离子掺杂调控钴酸锌的电子结构以提高析氧反应活性  

Tailoring the electronic structure of ZnCo_(2)O_(4)by incorporating anions with low electronegativity to improve the water oxidation activity

作　　者：熊兵 葛良兵 雷雪颜 汪扬凯 杨吉文 李威威 李晓宁 程振祥 傅正平 陆亚林 Bing Xiong;Liangbing Ge;Xueyan Lei;Yangkai Wang;Jiwen Yang;Weiwei Li;Xiaoning Li;Zhenxiang Cheng;Zhengping Fu;Yalin Lu(CAS Key Laboratory of Materials for Energy Conversion,Department of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China;Institute for Superconducting and Electronic Materials(ISEM),University of Wollongong,Wollongong 2500,Australia;Anhui Laboratory of Advanced Photon Science and Technology,University of Science and Technology of China,Hefei 230026,China;Synergetic Innovation Center of Quantum Information&Quantum Physics,Hefei National Research Center for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]CAS Key Laboratory of Materials for Energy Conversion,Department of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China [2]Institute for Superconducting and Electronic Materials(ISEM),University of Wollongong,Wollongong 2500,Australia [3]Anhui Laboratory of Advanced Photon Science and Technology,University of Science and Technology of China,Hefei 230026,China [4]Synergetic Innovation Center of Quantum Information&Quantum Physics,Hefei National Research Center for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China Materials》2023年第5期1793-1800,共8页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(U2032154);the Key Research and Development Program of Anhui(202004a05020072);Anhui Initiative in Quantum Information Technologies(AHY100000);Anhui Provincial Natural Science Foundation(1908085ME119)。

摘　　要：电子结构和电导率是析氧反应活性的重要描述符,它们可以通过掺杂来调节.鉴于金属掺杂通常会减少电催化剂的活性位点数量,本工作探究了阴离子掺杂对尖晶石钴酸锌(ZCO)电子结构及其析氧活性的影响.与三价钴为主的ZCO相比,用电负性较低的硫取代氧会提高低自旋态(t_(2g)-^(6)e_(g)^(1))二价钴的占比,其析氧活性要高于低自旋态的三价钴(t_(2g)-^(6)e_(g)^(0)).掺硫钴酸锌(ZCO-S)中钴离子和阴离子之间的电子密度的再分布导致了二价钴的增多,而且钴和硫离子间的强共价作用也会加速电荷迁移.ZCO-S在1.65伏(相对于可逆氢电极)下的比活性比原始ZCO高11倍.相反,掺入具有较高电负性和价态的氟(F)并不能有效地改善电子结构,最终导致材料析氧活性的降低.本工作建立了所掺阴离子的电负性与钴酸锌本征析氧活性之间的联系,并提供了一种通过掺杂不同电负性的阴离子来调控尖晶石氧化物的电子结构的简单有效的方法,这为合理设计高性能尖晶石电催化剂提供了新途径.Electron configurations and conductivity are significant descriptors/characteristics for the oxygen evolution reaction(OER),which can be modulated with heteroatom doping.Given that metal substitution usually reduces the number of active sites of spinel electrocatalysts,the effect of anion doping on the electronic structure has been investigated by using ZnCo_(2)O_(4)(ZCO)as a demonstration.Compared with Co^(3+)-dominated ZCO,the substitution of oxygen with less electronegative sulfur raises the portion of Co^(2+)in the lowspin states(t_(2g)-^(6)e_(g)^(1)),which is more OER-active than Co^(3+)(t_(2g)-^(6)e_(g)^(0)).Co^(2+)in the sulfur-doped ZCO(ZCO-S)is associated with the redistribution of electron density from S toward Co due to the high covalent interaction of Co–S.The Co–S interaction also induces a fast charge transfer.ZCO-S outperforms pristine ZCO by 11 times in terms of specific OER activity at 1.65 V versus reversible hydrogen electrode.In contrast,doping fluorine with higher electronegativity and valence deteriorates OER activity.Our work establishes the correlation between the electronegativity of anion dopants and OER intrinsic activity in spinel oxides and provides a simple and effective method to modulate the electronic structure of spinel oxides by doping anions with different electronegativities,which can be a new avenue for the rational design of high-performance spinel electrocatalysts.

关 键 词：oxygen evolution reaction anion doping ELECTRONEGATIVITY electronic structure SPINEL 

分 类 号：O643.36[理学—物理化学]