Boosting visible-light photocatalytic NO removal by non-intrinsic oxygen vacancies in graphitic carbon nitride.

Modifying photocatalysts for effective NO removal has profound implications for environmental protection. In this work, a novel g-C 3 N 4 containing non-intrinsic oxygen vacancies (V O -CN) is synthesized via a facile oxygen pre-doping followed by elimination. Compared to pristine g-C 3 N 4 , V O -CN exhibits remarkably enhanced visible-light photocatalytic activity, increasing NO removal by 54.3%, with high NO 3 ^- selectivity. This photocatalytic enhancement is attributed to the non-intrinsic oxygen vacancies introduced in Vo-CN. As comprehensively revealed by experimental characterizations coupled with density functional theory (DFT) calculations. The results show that the midgap state generated in the V O -CN electronic band structure accelerates photogenerated electron-hole separation. Additionally, the unique surface structure of V O -CN provides favorable channels for carrier migration while enhancing O 2 and NO adsorption. Consequently, the markedly improved generation of reactive oxygen species by Vo-CN promotes highly efficient NO removal. This work provides novel insights into designing high-performance g-C 3 N 4 -based photocatalysts for eliminating hazardous NO pollutants. [Display omitted] • Non-intrinsic oxygen vacancies enable excellent photocatalytic NO removal activity. • Effect of midgap states in band structure on photogenerated carrier behavior. • local electrons induced by oxygen vacancies facilitate carrier generation and migration. • Active oxygen species generation and subsequent oxidation of NO. [ABSTRACT FROM AUTHOR]