Enhanced Photocatalytic Antibacterial Property by Regulating the Built-in Electric Field of BiVO4 with a Piezoelectric Mineral Tourmaline

Photocatalytic antimicrobial materials represent a promising class of sustainable dis-infection technologies, leveraging the generation of reactive oxygen species (ROS) un-der light irradiation for environmental and biomedical applications. Bismuth vanadate (BiVO₄), a visible-light-responsive semiconductor, has garnered considerable interest due to its suitable bandgap and chemical stability. However, its photocatalytic per-formance is critically limited by rapid charge carrier recombination and a relatively weak intrinsic built-in electric field. In this study, we report a novel composite strategy to address these limitations by coupling BiVO₄ with tourmaline, a naturally abundant piezoelectric mineral exhibiting spontaneous polarization. The integration of tourma-line induces a built-in electric field that synergistically aligns with and amplifies the internal field of BiVO₄, which substantially improves charge separation and carrier transport dynamics. The resulting tourmaline/BiVO₄ heterostructure demonstrates remarkedly enhanced antibacterial activity under visible-light irradiation against both Escherichia coli and Staphylococcus aureus, significantly outperforming pristine BiVO₄. Mechanistic investigations attribute this enhancement to the polarization-induced modulation of interfacial charge dynamics, which boosts ROS generation and acceler-ates microbial inactivation kinetics. This work presents a generalizable strategy for the rational design of high-efficiency photocatalytic antimicrobial systems, offering poten-tial utility in water treatment, healthcare sterilization, and environmental remediation.