Comprehensive Review on Photocatalytic Degradation of Chlorpyrifos

Abstract

The current research focuses on the photocatalytic degradation of chlorpyrifos, an organophosphate insecticide whose usage is extensive because of its high efficacy despite being highly toxic and chemically stable. The review comprehensively discusses different photocatalytic systems and processes that have been used for the degradation of chlorpyrifos in aqueous media. Some of the current technologies that have drawn a lot of attention in chlorpyrifos degradation include; the advanced oxidation processes adopted from photocatalytic realm based on the use of semiconductors such as TiO2, ZnO, and their composites. The review draws focus on the aspects of catalyst loading, pH, light intensity and initial concentration of the pollutant affecting the degradation performance. Particular emphasis is paid on the state of the art in the preparation of the catalyst based on TiO2 modification techniques such as metal/non-metal doping, formation of heterojunction and surface sensitization to improve visible light utilization and photocatalytic activity. The degradation pathways and intermediate products are studied in detail in order to give more information about the complete mineralization. Furthermore, the review considers the real-life issues surrounding the usage of catalysts such as catalyst recovery, influence of the water matrix and scalability of the setup. The systematic review discussed herein will be beneficial to researchers and environmental engineers combating chlorpyrifos pollution, as well as provide insights for future study to enhance photocatalytic degradation effectiveness.

Key Words:  Photocatalytic degradation, Chlorpyrifos degradation, Insecticide, Photocatalysts, Metal doping.