Contribution of surface plasmonic resonance to enhanced photocatalytic antibacterial performance of graphene-based two-dimensional heterojunction

Abstract

Photo-responsive nanomaterials are promising antibiotic substitutes to treat bacterial infections. Although graphene-based two-dimensional (2D) heterojunction performs advantageous photo-excited antibacterial properties, constructing heterojunctions with matched photo-physical property is still an effective strategy for acquiring high-efficiency photo-antibacterial performance. Here, we constructed a surface plasmon resonance-enhanced graphene/bismuth oxychloride 2D heterojunction for photocatalytic antibacterial, via indirect light absorption of the heterojunction. The graphene-based 2D heterojunction displayed a bactericidal effect against S. aureus for 99.36 % under simulated sunlight irradiation for 20 min, which is much more efficient than pure BiOCl nanosheets. Furthermore, we investigated the contribution of indirect light absorption of two-dimensional heterojunction on photocatalytic antibacterial progress and found that graphene contributed 57.31 % of the antibacterial properties of heterojunction. The graphene can transfer the directly excited electrons of BiOCl semiconductor with the conjugate structure. And the enhanced photocatalytic antibacterial performance is mainly due to the surface plasmon resonance effect of graphene under irradiation of visible light, accelerating the transmission rate of photogenerated charge carriers. This study facilitated an in-depth understanding of the mechanism of visible-light-driven antibacterial and provided an ideal strategy for acquiring highly efficient photocatalytic antibacterial.