催化学报 ›› 2024, Vol. 67: 176-185.DOI: 10.1016/S1872-2067(24)60175-0

• 论文 • 上一篇    下一篇

CoOx促进Mo掺杂BiVO4光电催化H2O2合成及原位降解污染物

田甜a(), 王婉婷a, 王怡萍a, 李可欣a, 李园园c, 付文升a(), 丁勇b()   

  1. a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
    b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
    c重庆第二师范学院生物与工程学院, 重庆 400067
  • 收稿日期:2024-08-25 接受日期:2024-10-24 出版日期:2024-12-18 发布日期:2024-11-30
  • 通讯作者: 田甜,付文升,丁勇
  • 基金资助:
    国家自然科学基金(52102356);国家自然科学基金(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(KJQN202000544);重庆市教委科技研究计划(KJZD-K201900503);重庆市教委科技研究计划(KJQN202400522);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)

Mo-doping and CoOx loading over BiVO4 photoanode for enhancing performance of H2O2 synthesis and in-situ organic pollutant degradation

Tian Tiana(), Wanting Wanga, Yiping Wanga, Kexin Lia, Yuanyuan Lic, Wensheng Fua(), Yong Dingb()   

  1. aChongqing Key Laboratory of Green Catalysis Materials and Technology, College of Chemistry, Chongqing Normal University, Chongqing 401331, China
    bState 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
    cDepartment of Biological and Chemical Engineering, Chongqing University of Education, Chongqing 400067, China
  • Received:2024-08-25 Accepted:2024-10-24 Online:2024-12-18 Published:2024-11-30
  • Contact: Tian Tian, Wensheng Fu, Yong Ding
  • Supported by:
    National Natural Science Foundation of China(52102356);National Natural Science Foundation of China(22075119);Bayu Scholar Program(YS2022029);Chongqing Research Program of Basic Research and Frontier Technology(cstc2020jcyj-msxmX0939);Science and Technology Research Program of Natural Science Foundation of Chongqing, China(cstc2021ycjh-bgzxm0037);Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202000544);Science and Technology Research Program of Chongqing Municipal Education Commission(KJZD-K201900503);Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202400522);Doctor Start/Talent Introduction Program of Chongqing Normal University(21XLB014);Special Funding for Postdoctoral Research Projects in Chongqing(2023CQBSHTB2004)

摘要:

光电催化阳极水氧化合成过氧化氢(H2O2)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H2O2的合成. 光阳极氧化水制备H2O2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). BiVO4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H2O2材料. 但是, BiVO4光电极表面反应速率较慢、H2O2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BiVO4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BiVO4光电极制备H2O2的选择性和稳定性. 首先通过Mo的掺杂得到Mo-BiVO4光电极. 其次, 在Mo-BiVO4光阳极表面进行了钴氧化物(CoOx)助催化剂的修饰制得CoOx/Mo-BiVO₄电极. 在1.76 VRHE的条件下, BiVO4的电流密度是2.4 mA cm‒2. 在相同电位下, Mo-BiVO4的电流密度上升到2.9 mA cm‒2, CoOx/Mo-BiVO4的电流密度高达4.0 mA cm‒2. 实验结果表明, CoOx/Mo-BiVO₄光阳极在1.7 V vs. RHE的电位下H2O2的产率为0.39 μmol min‒1 cm‒2, 远高于Mo-BiVO4 (0.18 μmol min‒1 cm‒2)和BiVO4 (0.07 μmol min‒1 cm‒2). 在此电压下CoOx/Mo-BiVO4对H2O2合成的选择选择性为76.9%, 而Mo-BiVO4和BiVO4选择性分别为47.5%和32.0%. 这表明Mo的掺杂和CoOx的负载提高了BiVO4电极制备H2O2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BiVO4表面能带的弯曲程度, 有利于光电极表面H2O2的生成. CoOx的负载进一步减小了Mo-BiVO4光电极的能带弯曲程度, 同时抑制了H2O2的分解. 通过莫特肖特基曲线得出CoOx/Mo-BiVO4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CoOx的负载减小了BiVO4光电极表面载流子的复合. 在1.23 VRHE条件下测试结果表明, 与BiVO4和Mo-BiVO4相比,CoOx/Mo-BiVO4具有最好的稳定性. 密度泛函理论计算结果揭示了CoOx的负载提高了Mo-BiVO4光阳极生成H2O2的效率. 此外, CoOx/Mo-BiVO4光电极原位生成的H2O2被用于降解水溶液中的四环素, 结果表明, CoOx/Mo-BiVO4在所合成的电极中显示出最佳的降解效果. 通过液质联用探究了CoOx/Mo-BiVO4在降解盐酸四环素中的产物, 并且提出了降解盐酸四环素可能的反应机理.

综上所述, 本文揭示了掺杂和负载助催化剂可有效提升BiVO4电极光电合成H2O2的选择性和稳定性, 为高效光电催化合成H2O2体系的设计提供新的思路.

关键词: 过氧化氢, BiVO4光阳极, 助催化剂, 水氧化反应, 四环素降解

Abstract:

The combination of photoelectrochemical water oxidation hydrogen peroxide (H2O2) 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 H2O2. In this study, to promote H2O2 production, the surface of a Mo doped BiVO4 photoanode was modified with CoOx co-catalyst. The resulting CoOx/Mo-BiVO4 photoanode generates H2O2 at a rate of 0.39 μmol min-1 cm-2 with a selectivity of 76.9% at 1.7 VRHE. The experimental results indicate that CoOx decorated on Mo-BiVO4 kinetically favors the H2O2 production via reduced band bending, while inhibiting H2O2 decomposition. According to density functional theory calculations, the loading of CoOx enhances the efficiency of the Mo-BiVO4 photoanode in generating H2O2. Moreover, the in-situ generated H2O2 through CoOx/Mo-BiVO4 was applied to the degradation of tetracycline in aqueous solution, finding that CoOx/Mo-BiVO4 exhibits the best performance among the catalysts evaluated. This work demonstrates that the CoOx co-catalyst can effectively facilitate the water oxidation to H2O2, opening a way for its application in situ water remediation.

Key words: Hydrogen peroxide, BiVO4 photoanode, Co-catalyst, Water oxidation reaction, Tetracycline degradation