Investigation of photocatalytic chlorpyrifos degradation by a new silica mesoporous material immobilized by WS<sub>2</sub> and Fe<sub>3</sub>O<sub>4</sub> nanoparticles: Application of response surface methodology
Sanaz Merci, Asma Saljooqi, Tayebeh Shamspur, Ali Mostafavi
Abstract
In the present research, Fe 3 O 4 and WS 2 nanoparticles immobilized on or in KIT‐6 (KIT: Korea Institute of Science and Technology) pores (KIT‐6/WS 2 ‐Fe 3 O 4 ) were synthesized and studied as a photocatalyst for degradation of representative chlorpyrifos as an organophosphorus pesticide. In addition, the KIT‐6/WS 2 ‐Fe 3 O 4 photocatalyst was characterized by different methods such as TEM, FESEM‐EDS‐Mapping, XRD, and N 2 adsorption/desorption surface area, in order to understand their morphology, structural, and physical properties. The photocatalytic performance of this photocatalyst was investigated for degradation of chlorpyrifos by visible light irritation. The effects of variables such as chlorpyrifos concentration, KIT‐6/WS 2 ‐Fe 3 O 4 nanocatalyst amount, pH, and irradiation time on chlorpyrifos degradation efficiency was studied by central composite design with response surface methodology. The optimum conditions for CP degradation were obtained by 50 mg KIT‐6/WS 2 ‐Fe 3 O 4 nanocatalyst, and 7.2 ppm chlorpyrifos solution with pH = 6, at 52 min. The pseudo‐first‐order model with rate constants equal to 0.069 min −1 as best choice efficiency described the chlorpyrifos degradation process according to Langmuir‐Hinshelwood kinetic.