Defect-Type-Dependent Near-Infrared-Driven Photocatalytic Bacterial Inactivation by Defective Bi₂ S₃ nanorods

Defect engineering is crucial in tailoring photocatalytic efficiency, but it suffers from uncertainty in determining the vacancy type and in which type of the vacancy can better promote the photocatalytic efficiency. In this study, Bi₂ S₃ nanorods with bismuth or sulfur vacancies were synthesized to investigate their distinct effects on the electronic structure, electron-hole separation characteristics, and near-infrared (NIR)-driven photocatalytic bacterial inactivation activity. Both bismuth and sulfur vacancies can enhance the light absorption ability of Bi₂ S₃ . However, the lifetime of photoinduced electrons is extended by bismuth vacancies but shortened by sulfur vacancies. Owing to these tendencies, Bi₂ S₃ with Bi vacancies fully inactivated 7 log E. coli cells within 40 min of NIR irradiation, displaying better NIR-driven photocatalytic bacterial inactivation efficiency than Bi₂ S₃ with S vacancies. This study discloses the defect-type-dependent photocatalytic behaviors, providing new insights into designing highly efficient photocatalysts.