Removal of chlorpyrifos, an insecticide using metal free heterogeneous graphitic carbon nitride (g-C3N4) incorporated chitosan as catalyst: Photocatalytic and adsorption studies.

Abstract

The present study investigates the photocatalytic degradation of an organic pesticide using a metal free heterogeneous graphitic carbon nitride (g-C3N4) incorporated into chitosan as catalyst. Chlorpyrifos (O, O-diethylO-3,5,6-trichloro-2-pyridyl phosphorothioate (CPFS)), an insecticide includes in a class of Organophosphate pesticides with a chemical formula (C9H11Cl3NO3PS). It is widely used in agricultural lands to control pests in cotton, fruit and vegetables. The acute toxicity of chlorpyrifos is still dangerous to all aquatic living organisms. The CS/g-C3N4 materials have been characterized using UV-vis spectrophotometer (UV-vis), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Energy Dispersive X-ray Analysis (EDX), Thermal analysis (TGA-DSC), Chemical oxygen demand (COD), X-ray diffraction (XRD), Diffuse reflectance spectra (DRS) and Electron spin resonance (ESR). The degradation of pesticide using CS/g-C3N4 showed good efficiency of about 85%. The results suggest that CS/g-C3N4 composite is a good alternative for the treatment of chlorpyrifos in aqueous solution. We have proposed a novel photocatalyst by metal free heterogeneous graphitic carbon using melamine and its recombination effects were minimized by chitosan which act as an electron carrier. The enhanced photocatalytic performance could be attributed to an efficient separation of electron-hole pairs through a Z-scheme mechanism, in which chitosan acted as charge separation carriers.