{"title":"Oxygen-vacancy-mediated photocatalytic activity of antimony molybdenum oxide toward green ammonia synthesis","authors":"Botong Liu, Ling Huang, Terence Musho, Chih-Jung Chen, Chung-Li Dong, Chaoyun Tang, Alhassan Yasin, Yulei Wang, Hui Yang, Joeseph Bright, Peng Zheng, Ru-Shi Liu, Nianqiang Wu","doi":"10.1016/j.checat.2025.101337","DOIUrl":null,"url":null,"abstract":"Oxygen vacancies in metal oxide photocatalysts are essential to activate photocatalytic activity toward nitrogen fixation, although their roles and underlying mechanisms remain poorly understood. Unfortunately, oxygen vacancies are prone to disappear during photocatalysis processes. Herein, antimony molybdate (Sb<sub>2</sub>MoO<sub>6</sub>) is proposed as a photocatalyst for green ammonia synthesis, which achieves ammonia generation rate of 6.39 μM h<sup>−1</sup>⋅g<sup>−1</sup>. Oxygen vacancies modulate the MoO<sub>6</sub> octahedra, not the tetrahedral, SbO<sub>4</sub> bilayers in the triclinic structure of Sb<sub>2</sub>MoO<sub>6</sub> and result in partial reduction of Mo<sup>6+</sup> to Mo<sup>5+</sup>. Instead of oxygen vacancies themselves, Mo<sup>5+</sup> serves as active sites, favoring surface adoption of N<sub>2</sub> and formation of reaction intermediates. Oxygen vacancies are predominantly refilled over extended photocatalysis, leading to conversion of Mo<sup>5+</sup> back to Mo<sup>6+</sup> and consequent photocatalyst deactivation. Therefore, cobalt dopant is introduced to stabilize the oxygen vacancies effectively. The scientific insights obtained will guide the development of stable photocatalysts for green ammonia synthesis.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"13 1","pages":""},"PeriodicalIF":11.5000,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chem Catalysis","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1016/j.checat.2025.101337","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Oxygen vacancies in metal oxide photocatalysts are essential to activate photocatalytic activity toward nitrogen fixation, although their roles and underlying mechanisms remain poorly understood. Unfortunately, oxygen vacancies are prone to disappear during photocatalysis processes. Herein, antimony molybdate (Sb2MoO6) is proposed as a photocatalyst for green ammonia synthesis, which achieves ammonia generation rate of 6.39 μM h−1⋅g−1. Oxygen vacancies modulate the MoO6 octahedra, not the tetrahedral, SbO4 bilayers in the triclinic structure of Sb2MoO6 and result in partial reduction of Mo6+ to Mo5+. Instead of oxygen vacancies themselves, Mo5+ serves as active sites, favoring surface adoption of N2 and formation of reaction intermediates. Oxygen vacancies are predominantly refilled over extended photocatalysis, leading to conversion of Mo5+ back to Mo6+ and consequent photocatalyst deactivation. Therefore, cobalt dopant is introduced to stabilize the oxygen vacancies effectively. The scientific insights obtained will guide the development of stable photocatalysts for green ammonia synthesis.
期刊介绍:
Chem Catalysis is a monthly journal that publishes innovative research on fundamental and applied catalysis, providing a platform for researchers across chemistry, chemical engineering, and related fields. It serves as a premier resource for scientists and engineers in academia and industry, covering heterogeneous, homogeneous, and biocatalysis. Emphasizing transformative methods and technologies, the journal aims to advance understanding, introduce novel catalysts, and connect fundamental insights to real-world applications for societal benefit.