Highly efficient photocatalytic decomposition of triazophos using novel In2O3/WO3 nanocomposites with oxygen defects and S-Scheme heterojunctions

Abstract

Confronted with the substantial environmental threat posed by organophosphorus pesticides, the urgency to develop reliable and efficient mitigation strategies is paramount. Photocatalytic technology, which catalyzes the generation of potent oxidizing radicals, emerges as a promising solution. In this study, we have successfully synthesized In2O3/WO3 (IO/WO) nanocomposites, endowed with oxygen defects and S-scheme heterojunctions, exhibiting exceptional photocatalytic degradation activity and mineralization efficiency. Notably, the WO material synthesized in this study is blue in color, unlike the traditional yellow color of WO, indicating a rich presence of oxygen defects. The 60-IO/WO nanocomposite, containing 60 % IO, achieved superior photocatalytic degradation, reducing triazophos pesticide from 100 % to 21.29 % within 60 min, outperforming the individual materials IO (56.97 %) and WO (48.02 %). This nanocomposite also exhibited remarkable corrosion resistance across multiple cycles, showcasing significantly enhanced stability compared to the individual IO and WO materials. Electron paramagnetic resonance (EPR) spectroscopy confirmed the presence of oxygen defects in the blue WO, while both EPR and theoretical calculations substantiated the formation of the S-scheme heterojunction in the 60-IO/WO nanocomposite. The new nanocomposite's excellent photocatalytic degradation activity is influenced by various factors such as differing surface areas, composite amounts, photocurrent responses, and resistances, all of which impact the degradation performance of triazophos. Compared to traditional photocatalytic materials, the IO/WO nanocomposite demonstrates a significant edge in photocatalytic efficiency and chemical stability, offering considerable potential for environmental remediation, especially in the degradation of organophosphorus pesticides.