Jointly augmented photocatalytic NO removal by S-scheme Bi12SiO20/Ag2MoO4 heterojunctions with surface oxygen vacancies

Fei Chang; Shanshan Zhao; Yibo Lei; Xiaomeng Wang; Fan Dong; Gangqiang Zhu; Yuan Kong

doi:10.1016/j.jcis.2023.06.168

Jointly augmented photocatalytic NO removal by S-scheme Bi₁₂SiO₂₀/Ag₂MoO₄ heterojunctions with surface oxygen vacancies

J Colloid Interface Sci. 2023 Nov:649:713-723. doi: 10.1016/j.jcis.2023.06.168. Epub 2023 Jun 25.

Authors

Fei Chang¹, Shanshan Zhao¹, Yibo Lei¹, Xiaomeng Wang¹, Fan Dong², Gangqiang Zhu³, Yuan Kong⁴

Affiliations

¹ School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, PR China.
² Research Center for Environmental Science & Technology, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, PR China.
³ School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062, PR China. Electronic address: zgq2006@snnu.edu.cn.
⁴ Hefei National Laboratory for Physical Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics CAS Center for Excellence in Nanoscience and Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, PR China. Electronic address: feichang@usst.edu.cn.

PMID: 37385036
DOI: 10.1016/j.jcis.2023.06.168

Abstract

The deep oxidation of NO molecules to NO₃^- species with the avoidance of toxic NO₂ generation is a big and challengeable concern, which can be solved by the rational design and construction of catalytic systems with satisfactory structural and optical features. For such, in this investigation binary composites Bi₁₂SiO₂₀/Ag₂MoO₄ (BSO-XAM) were fabricated through a facile mechanical ball-milling route. From microstructural and morphological analyses, heterojunction structures with surface oxygen vacancies (OVs) were simultaneously created, contributing to the enhanced visible-light absorption, reinforced migration and separation of charge carries, and further boosted generation of reactive species such as superoxide radicals and singlet oxygen. Based on the density-functional theory (DFT) calculations, surface OVs induced the strengthened adsorption and activation of O₂, H₂O, and NO molecules and oxidation of NO to NO₂, while heterojunction structures were beneficial for the continuous oxidation of NO₂ to NO₃^- species. Thus, the heterojunction structures with surface OVs synergistically guaranteed the augmented photocatalytic NO removal and constrained NO₂ generation of BSO-XAM through a typical S-scheme model. This study may provide scientific guidances for the photocatalytic control and removal of NO at ppb level by Bi₁₂SiO₂₀-based composites through the mechanical ball-milling protocol.

Keywords: Ag(2)MoO(4); Ball-milling; Bi(12)SiO(20); Oxygen vacancies; Photocatalytic NO removal.