Innovative fabrication of Ceo2 nanoparticles/WO3 nanoplates S-Scheme heterojunction for visible light photocatalytic degradation of nitenpyram insecticide

In the current study, a novel S-scheme heterojunction photocatalyst was fabricated through a simple hydrothermal method from CeO2 nanoparticles and WO3 nanoplates in presence of tragacanth mucilage as natural surfactant. The prepared heterojunction photocatalyst was used for degradation of Nitenpyram insecticide under visible light irradiation. The successful synthesis of the heterojunction samples was confirmed by FESEM, XRD, PL, DRS, and Mott-Schottky analysis. The results showed that, the photocatalytic performance of the CeO2/WO3 heterojunction sample was higher than that of the pure WO3 and CeO2 samples. The highest photocatalytic activity was obtained for the sample with 30 wt% CeO2 content, which has the reaction rate constant of 0.017 min-1. The improved photocatalytic activity of the nanocomposite sample could be related to the efficient separation of the photoinduced electron-hole pairs at the interfaces of WO3 and CeO2, and enhanced visible light harvesting. Furthermore, according to the active species trapping tests and Mott-Schottky measurements, hydroxide radical was determined as the main active species for degradation of Nitenpyram insecticide, and a S-scheme charge transfer mechanism revealed to be responsible for the enhanced photocatalytic performance.