Innovative fabrication of Ceo۲ nanoparticles/WO۳ 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 CeO۲ nanoparticles and WO۳ 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 CeO۲/WO۳ heterojunction sample was higher than that of the pure WO۳ and CeO۲ samples. The highest photocatalytic activity was obtained for the sample with ۳۰ wt% CeO۲ content, which has the reaction rate constant of ۰.۰۱۷ min-۱. 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 WO۳ and CeO۲, 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.

Keywords:

CeO۲ , Heterojunction , Nitenpyram , S-Scheme , WO۳