Construction of a g-C3N4/Bi(OH)3 Heterojunction for the Enhancement of Visible Light Photocatalytic Antibacterial Activity

Photocatalytic technology has been recently conducted to remove microbial contamination due to its unique features of nontoxic by-products, low cost, negligible microbial resistance and broad-spectrum elimination capacity. Herein, a novel two dimensional (2D) g-C3N4/Bi(OH)(3) (CNB) heterojunction was fabricated byincorporating Bi(OH)(3) (BOH) nanoparticles with g-C3N4 (CN) nanosheets. This CNB heterojunction exhibited high photocatalytic antibacterial efficiency (99.3%) against Escherichia coli (E. coli) under visible light irradiation, which was 4.3 and 3.4 times that of BOH (23.0%) and CN (28.0%), respectively. The increase in specific surface area, ultra-thin layered structure, construction of a heterojunction and enhancement of visible light absorption were conducive to facilitating the separation and transfer of photoinduced charge carriers. Live/dead cell staining, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) assays and scanning electron microscopy (SEM) have been implemented to investigate the damage to the cell membrane and the leakage of the intracellular protein in the photocatalytic antibacterial process. The e(-), h(+) and O-2(center dot-) were the active species involved in this process. This study proposed an appropriate photocatalyst for efficient treatment of bacterial contamination.