Metal Decorated–ZnO and TiO2 Nanocomposites for Degradation of Organic Pollutants—A Mini Review

Water pollution caused by harmful organic pollutants discharged from various industries, such as textiles, pharmaceuticals, papermaking, and printing, is resulting in serious health complications and adversely impacting aquatic life. Numerous strategies/methods have been employed to remove these pollutants from water streams. Amongst them, photocatalysts have proven effective in tackling these issues. Zinc oxide (ZnO) and titanium Dioxide (TiO2) photocatalysts are at the forefront due to their exceptional properties, which render them ideal for wastewater treatment. However, their full capacity as photocatalysts is limited by the wide band gap and faster electron-hole recombination rates. Metal decoration on the surface of these semiconductors is one of the fascinating strategies to address these limitations. In this brief review, the synthesis, morphology, and photocatalytic activity of ZnO and TiO2 decorated with metal nanoparticles (NPs) towards the degradation of harmful organic pollutants from various industries are presented. Metal decoration of the surface of ZnO and TiO2 is a viable method to enhance the photocatalytic activity of these semiconductors, particularly under visible light.