Photocatalytic Degradation of Microplastics: Mechanism, Recent Developments, and Associated Threats

Microplastics are ubiquitous emerging contaminants which poses severe threat to the environment. Advanced oxidation processes (AOPs) are novel efficient technique for the elimination of such emerging contaminants. Photocatalysis is an AOP that is environment friendly, and can be used to convert microplastics to various degradation products. Photocatalytic degradation proceeds with the generation of reactive oxygen species (ROS) and oxidative radicals leading to polymer degradation and ultimate mineralization.Some of the photocatalysts exhibited good performance in degradation of microplastics and doping of semiconductor photocatalysts with metals and non-metals was found to be beneficial.Leaching of additives, toxicity of intermediate products, carrier potential of degraded microplastics and nanotoxicity of photocatalysts are some of the threats posed by the photocatalytic degradation of microplastics. This bookchapter summarizes the degradation mechanism of microplastics using photocatalysts along with the recent developments in photocatalytic degradation of various plastics. Furthermore, the threats associated with photocatalytic degradation of microplastics are also discussed.