Photocatalytic degradation of imidacloprid using GO/Fe3O4/TiO2-NiO under visible radiation: Optimization by response level method

Abstract

Imidacloprid (IC) pesticide is used as a poison for a specific group of living organisms. On the other hand, modern insecticides in the aquatic environment will have serious problems for humans and other living organisms. Photocatalytic degradation can be a promising way to improve water. In the present work, the TiO2-NiO magnetic on nanostructure graphene oxide nanosheets were synthesized using the sol–gel method and after characterization was used as photocatalyst for degradation of organophosphorus pesticides under visible light irradiation. Parameters affecting the process including photocatalyst amount, pesticide concentration, pH, radiation time, and temperature effect on the percentage of imidacloprid degradation were investigated and optimized. The degradation percent of organophosphorus pesticides was carried out using UV–Vis spectrophotometer. In order to optimize the parameters affecting the degradation process, the response surface method (RSM) was successfully applied. The response surface method is based on the central composite design (CCD). The CCD was successful in optimizing the photocatalytic degradation of imidacloprid pesticide. The pH, photocatalyst amount, the concentration of imidacloprid pesticide were investigated and the second-order variance (ANOVA) analysis showed that the predicted values correspond with the results of the experiment. The results indicate that GO/Fe3O4/TiO2-NiO could act as a suitable photocatalyst under visible light in the degradation of organophosphorus pesticides.