Enhanced visible-light-driven photocatalytic antibacterial activity by in-situ synthesized NH₂-MIL-101(Al)/AgI heterojunction and mechanism insight

Photocatalytic antibacterial technology has the potential to prevent the formation of biofilms and microbial corrosion of metals by rapidly eliminating microorganisms in a short period. In this study, novel NH₂-MIL-101(Al)/AgI is in-situ synthesized at ambient temperature, revealing enhanced photocatalytic antibacterial activity and cyclic stability in seawater. A low dosage of 0.1 mg mL^-1 NH₂-MIL-101(Al)/AgI sterilizes almost all Staphylococcus aureus within 60 min, and all Pseudomonas aeruginosa within 20 min upon visible light irradiation. Microscopic characterizations, photoelectrochemical experiments, and finite element method simulation indicate that the uniform dispersion of AgI nanoparticles and the formation of NH₂-MIL-101(Al)/AgI Z-type heterojunction enhance the visible light absorption of NH₂-MIL-101(Al), suppress the recombination of the photogenerated carriers, and improve the transfer efficiency. The photocatalytic antibacterial mechanism is also proposed based on the generation of h⁺, e⁻, and reactive oxygen species (especially ¹O₂) which induced the rupture of cell structures. Hence, the NH₂-MIL-101(Al)-related material is introduced for photocatalytic antibacterial applications and offers insights for protecting metals from microbial corrosion in marine environments.