Construction of visible light responsive GO-stimulated In2O3/BiVO4 Z-scheme heterostructure: Photocatalytic degradation of dye & antibiotics, anticancer activity and toxicity elimination

Abstract

A ternary nanocomposite, In2O3/GO/BiVO4, was created using the hydrothermal process, establishing a heterojunction between In2O3 and BiVO4 with the addition of graphene oxide nanosheets. The synthesized materials underwent characterization using various standard analytical techniques, including diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), electron spin resonance spectroscopy (ESR), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM). The developed materials showed notable efficacy in degrading MB dye and antibiotics such as ciprofloxacin and tetracycline, when exposed to visible light in an aqueous suspension. The photocatalyst, 10 wt% In2O3/GO/BiVO4 (10IBG) showed better activity compared with the pure and other composite materials. The enhanced activity could be attributed to the synergistic effects of charge carrier separation and electron mediation facilitated by graphene oxide via Z-scheme pathway. The successful integration of graphene oxide in the heterostructure underscores its potential as a promising strategy for developing high-performance photocatalysts for the elimination of organic pollutants. Furthermore, the mechanism investigation underlying photocatalytic degradation of organic pollutants using the 10IBG heterostructure photocatalyst is conducted through trapping experiments, which indicates that the degradation is primarily contributedby superoxide radical anions (O2•-) and hydroxyl radicals (•OH). Moreover, 10IBG photocatalyst displayed remarkable anticancer activity against A549 lung cancer cell lines, whereas the cell viability was reduced from 18% in the dark medium to 58% when exposed to visible light. In terms of toxicity assessment, the 10IBG heterostructure photocatalyst demonstrated quick eradication of antibiotic toxicity and established itself as a promising and cost-effective photocatalyst for wastewater treatment.