Metal Oxides-Based Nano/Microstructures for Photodegradation of Microplastics

The ubiquitous presence of microplastics in the environment has raised serious environmental and health concerns. These tiny plastic particles can enter the food chain, posing a significant threat to human health. Researchers worldwide have focused their efforts on developing strategies to mitigate microplastic pollution. This review focuses on the potential of nano/microstructured metal oxide semiconductors as effective photocatalysts for microplastic degradation. The review is divided into two sections: static metal oxides and dynamic micromachines based on metal oxides. The modifications made to nano/microstructured metal oxides such as TiO2, ZnO, bismuth oxyhalides (BiOX), NiO, Cu2O/CuO, perovskite-like Bi2WO6, Fe3O4, etc., to enhance their degradation efficiency are thoroughly discussed and reviewed. Additionally, the photocatalytic pathways for the conversion of microplastics into C-2 fuel and other value-added products are also elaborated. The current developments in the realm of dynamic, self-propelled, and controlled micromotors for the photodegradation of microplastics are also highlighted. The review concludes by proposing future perspectives and challenges to facilitate the remediation of microplastics in water and wastewater systems in a more effective, scalable, and environmentally friendly manner. Overall, the review emphasizes the potential of photocatalysis using nano/microstructured metal oxide semiconductors as an eco-friendly and promising approach for microplastic degradation.