ANovel <i>InSitu</i> Biosynthesized BacterialCellulose/MoS₂/TiO₂ Composite Film for EfficientRemoval of Dyes and Pathogenic Bacteria from Industrial Wastewaterunder Sunlight Illumination

Developing multifunctional water purification materials is of great significance for the elimination of organic pollutants and bacterial pathogens in industrial wastewater. Herein, we report a novel green material, bacterial cellulose/molybdenum disulfide/titanium oxide (BC/MoS₂/TiO₂) composite film, through one-step <i>in situ</i> biosynthesis, and its application in industrial wastewater treatment. The systematic physicochemical characterization of BC/MoS₂/TiO₂ demonstrated that MoS₂ and TiO₂ were effectively incorporated into the BC porous network matrix. Meanwhile, BC/MoS₂/TiO₂ was absorbed in the UV, visible, and NIR regions with a bandgap of 1.93 eV, indicating that it can serve as a sunlight-excited photocatalyst. Further photocatalytic studies revealed that the synergistic effect of MoS₂ and TiO₂ enabled BC/MoS₂/TiO₂ to generate large amounts of •OH and O₂^•–, and the potential photocatalytic mechanism was investigated. Additionally, BC/MoS₂/TiO₂ exhibited higher photodegradation efficiencies against methylene blue (<i>k</i> = 0.01963 min^–1) and rhodamine B (<i>k</i> = 0.01844 min^–1), as well as better photodynamic and photothermal antibacterial performances against Staphylococcus aureus (99.9929%) and Escherichia coli (99.8935%) than BC/MoS₂ or BC/TiO₂ alone. BC/MoS₂/TiO₂ showed great reusability and maintained its effectiveness after four cycles. Overall, these results revealed that the biosynthesized BC/MoS₂/TiO₂ achieved favorable photodegradation of organic dye pollutants via a type I photodynamic pathway under sunlight illumination and synergistic photothermal and photodynamic antimicrobial activity, thus suggesting that this mild, green, and sustainable composite is a promising material for efficient antibacterial and degradation of industrial wastewater constituents.