2D TiO2 nanosheets decorated via sphere-like BiVO4: a promising non-toxic material for liquid phase photocatalysis and bacterial eradication

ChemSusChem. 2024 Apr 8:e202400027. doi: 10.1002/cssc.202400027. Online ahead of print.

Abstract

An in-depth investigation was conducted on a promising composite material (BiVO4/TiO2), focusing on its potential toxicity, photoinduced catalytic properties, as well as its antibiofilm and antimicrobial functionalities. The preparation process involved the synthesis of 2D-TiO2 using the lyophilization method, which was subsequently functionalized with sphere-like BiVO4. Finally, we developed BiVO4/TiO2 S-scheme heterojunctions which can greatly promote the separation of electron-hole pairs to achieve high photocatalytic performance. The evaluation of concentration- and time-dependent viability inhibition was performed on human lung carcinoma epithelial A549 cells. This assessment included the estimation of glutathione levels and mitochondrial dehydrogenase activity. Significantly, the BiVO4/TiO2 composite demonstrated minimal toxicity towards A549 cells. Impressively, the BiVO4/TiO2 composite exhibited notable photocatalytic performance in the degradation of rhodamine B (k =0.135 min-1) and phenol (k = 0.016 min-1). In terms of photoinduced antimicrobial performance, the composite effectively inactivated both gram-negative E. coli and gram-positive E. faecalis bacteria upon 60-min of UV-A light exposure, resulting in a significant log6(log10CFU/mL) reduction in bacterial count. These promising results can be attributed to the unique 2D morphology of TiO2 modified by sphere-like BiVO4, leading to an increased generation of (intracellular)hydroxyl radicals, which plays a crucial role in treatments of both organic pollutants and bacteria.

Keywords: 2D TiO2; Antimicrobial; Photocatalysis; cytotoxicity; sphere-like BiVO4.