Mo-doping and CoO_(x) loading over BiVO_(4) photoanode for enhancing performance of H_(2)O_(2) synthesis and in-situ organic pollutant degradation  

CoO_(x)促进Mo掺杂BiVO_(4)光电催化H_(2)O_(2)合成及原位降解污染物

作　　者：Tian Tian Wanting Wang Yiping Wang Kexin Li Yuanyuan Li Wensheng Fu Yong Ding 田甜;王婉婷;王怡萍;李可欣;李园园;付文升;丁勇(重庆师范大学化学学院,绿色催化材料与技术重庆市重点实验室,重庆401331;兰州大学化学化工学院,甘肃省先进催化重点实验室,功能有机分子化学国家重点实验室,甘肃兰州730000;重庆第二师范学院生物与工程学院,重庆400067)

机构地区：[1]Chongqing Key Laboratory of Green Catalysis Materials and Technology,College of Chemistry,Chongqing Normal University,Chongqing 401331,China [2]State Key Laboratory of Applied Organic Chemistry,Key Laboratory of Advanced Catalysis of Gansu Province,College of Chemistry and Chemical Engineering,Lanzhou University,Lanzhou 730000,Gansu,China [3]Department of Biological and Chemical Engineering,Chongqing University of Education,Chongqing 400067,China

出　　处：《Chinese Journal of Catalysis》2024年第12期176-185,共10页催化学报(英文)

基　　金：国家自然科学基金(52102356,22075119);重庆市巴渝学者青年项目(YS2022029);重庆市基础研究与前沿技术研究计划(cstc2020jcyj-msxmX0939);重庆市自然科学基金科技研究计划(cstc2021ycjh-bgzxm0037);重庆市教委科技研究计划(KJQN_(2)02000544,KJZD-K201900503,KJQN_(2)02400522);重庆师范大学博士启动/人才引进计划(21XLB014);重庆市博士后研究项目特别资助(2023CQBSHTB2004).

摘　　要：The combination of photoelectrochemical water oxidation hydrogen peroxide(H_(2)O_(2))on the anode and hydrogen evolution on the cathode increase the value of the water splitting process.However,the sluggish water oxidation kinetics and slow carrier transport limit the generation of H_(2)O_(2).In this study,to promote H_(2)O_(2) production,the surface of a Mo doped BiVO_(4) photoanode was modified with CoO_(x) co-catalyst.The resulting CoO_(x)/Mo-BiVO_(4) photoanode generates H_(2)O_(2) at a rate of 0.39μmol min-1 cm–2 with a selectivity of 76.9%at 1.7 VRHE.The experimental results indicate that CoO_(x) decorated on Mo-BiVO_(4) kinetically favors the H_(2)O_(2) production via reduced band bending,while inhibiting H_(2)O_(2) decomposition.According to density functional theory calculations,the loading of CoO_(x) enhances the efficiency of the Mo-BiVO_(4) photoanode in generating H_(2)O_(2).Moreover,the in-situ generated H_(2)O_(2) through CoO_(x)/Mo-BiVO_(4) was applied to the degradation of tetracycline in aqueous solution,finding that CoO_(x)/Mo-BiVO_(4) exhibits the best performance among the catalysts evaluated.This work demonstrates that the CoO_(x) co-catalyst can effectively facilitate the water oxidation to H_(2)O_(2),opening a way for its application in situ water remediation.光电催化阳极水氧化合成过氧化氢(H_(2)O_(2))耦合阴极制备氢气提高了光电水分解过程的效率和经济性.然而,缓慢的水氧化动力学和较慢的载流子传输限制了光电催化H_(2)O_(2)的合成.光阳极氧化水制备H_(2)O_(2)需要的电极电势(1.76 V vs.RHE)远高于水氧化的电极电势(1.23 V vs.RHE).BiVO_(4)光阳极合成方法简单、合成原料便宜,其价带位置位于2.4 eV(vs.RHE),是理想的光阳极水氧化H_(2)O_(2)材料.但是,BiVO_(4)光电极表面反应速率较慢、H_(2)O_(2)的选择性较低等缺点制约了其作为光电材料的进一步发展.因此,构筑高效的BiVO_(4)光电复合材料成为解决上述问题的有效途径.本文采用掺杂和表面负载助催化剂的方法提高了BiVO_(4)光电极制备H_(2)O_(2)的选择性和稳定性.首先通过Mo的掺杂得到Mo-BiVO_(4)光电极.其次,在Mo-BiVO_(4)光阳极表面进行了钴氧化物(CoO_(x))助催化剂的修饰制得CoO_(x)/Mo-BiVO_(4)电极.在1.76 VRHE的条件下,BiVO_(4)的电流密度是2.4 mA cm‒2.在相同电位下,Mo-BiVO_(4)的电流密度上升到2.9 mA cm‒2,CoO_(x)/Mo-BiVO_(4)的电流密度高达4.0 mA cm‒2.实验结果表明,CoO_(x)/Mo-BiVO_(4)光阳极在1.7 V vs.RHE的电位下H_(2)O_(2)的产率为0.39μmol min-1 cm‒2,远高于Mo-BiVO_(4)(0.18μmol min-1 cm‒2)和BiVO_(4)(0.07μmol min-1 cm‒2).在此电压下CoO_(x)/Mo-BiVO_(4)对H₂O₂合成的选择选择性为76.9%,而Mo-BiVO_(4)和BiVO_(4)选择性分别为47.5%和32.0%.这表明Mo的掺杂和CoO_(x)的负载提高了BiVO_(4)电极制备H_(2)O_(2)的产率和选择性.开光和黑暗条件下的开路电压差实验结果表明,Mo的掺杂减小了BiVO_(4)表面能带的弯曲程度,有利于光电极表面H_(2)O_(2)的生成.CoO_(x)的负载进一步减小了Mo-BiVO_(4)光电极的能带弯曲程度,同时抑制了H_(2)O_(2)的分解.通过莫特肖特基曲线得出CoO_(x)/Mo-BiVO_(4)具有最大的载流子浓度.瞬态和稳态荧光结果表明,Mo的掺杂和CoO_(x)的负�

关 键 词：Hydrogen peroxide BiVO_(4)photoanode CO-CATALYST Water oxidation reaction 

分 类 号：O64[理学—物理化学]