Dual sulfur vacancy pairs functionalized SnS2 for efficient photocatalytic molecular oxygen activation

Defect engineering is considered an effective means to improve the photocatalytic performance of semiconductors. However, current research on defects mainly focuses on single atom vacancies, lacking research on atomic vacancy pairs. In this work, we used SnS 2 as the research model and constructed SnS 2 nanostructures with rich S vacancies and dual S vacancy pairs, respectively. By comparing the photocatalytic activation O 2 performance of SnS 2 under different defect effects, it was found that dual S vacancy pairs have better performance optimization characteristics than S vacancies. Combining experiments and theoretical calculations, it is confirmed that dual S vacancy pairs have significant advantages over S vacancies in regulating the band structure, improving the separation efficiency of photogenerated charges and the migration rate of charge carriers, as well as activating the interface reaction of O 2 . In addition, when the catalyst is used for the removal of organic matter in water, it can be found that the optimization effect of dual defects on performance has good sustainability. This work contributes to a deeper understanding of the application scope of defect engineering and provides new ideas for the development of highly active photocatalysts.