Double Layer SiO₂-Coated Water-Stable Halide Perovskite as a Promising Antimicrobial Photocatalyst under Visible...

Halide perovskite nanocrystals (HPNCs) have emerged as promising materials for various light harvesting applications due to their exceptional optical and electronic properties. However, their inherent instability in water and biological fluids has limited their use as photocatalysts in the aqueous phase. In this study, we present highly water-stable SiO₂-coated HPNCs as efficient photocatalysts for antimicrobial applications. The double SiO₂ layer coating method confers long-term structural and optical stability to HPNCs in water, while the in situ synthesis of lead- and bismuth-based perovskite NCs into the SiO₂ shell enhances their versatility and tunability. We demonstrate that the substantial generation of singlet oxygen via energy transfer from HPNCs enables efficient photoinduced antibacterial efficacy under aqueous conditions. More than 90% of Escherichia coli was inactivated under mild visible light irradiation for 6 h. The excellent photocatalytic antibacterial performance suggests that SiO₂-coated HPNCs hold great potential for various aqueous phase photocatalytic applications.