Photocatalytic and electrochemical investigation of metal oxides for water pollutants degradation: an advanced oxidation process for environmental remediation

Water is a prime natural asset that supports life on biosphere covers about 71% of total earth surface area. Population explosion and significant industrial evolution have escalated the dilemma of aquatic resources contamination due to discharge of numerous pollutants including dyes, pesticides etc. Advanced Oxidation Processes (AOPs) have emerged as promising techniques for water purification, harnessing the oxidative power of catalysts to remediate these contaminants. Metal oxide nanocomposite owns to their unique physiochemical properties including low band gap energy, low recombination rate, cost effective, ecofriendly nature etc. have gained significant attention as catalyst in the AOPs processes. The investigation encompasses a comprehensive exploration of the photocatalytic degradation of water pollutants using metal oxides, with a focus on the roles of catalysts such as TiO2, ZnO, and Fe2O3 etc. with suitable degradation mechanism. Photocatalysis involves the generation of reactive oxygen species (ROS) under light irradiation, leading to the degradation of organic pollutants. On the other hand, synergistic effects of combining different metal oxide nanocomposite exhibit enhanced catalytic activity, conductivity and stability compared to their bulk counterparts, making them suitable candidate for electrochemical processes such as water splitting, metal deposition and electrode materials in energy storage devices. Overall, this review provides detailed view on challenges and future prospects of metal oxide nanocomposites are addressed, emphasizing the need for scalable synthesis, improved stability under harsh conditions and a deeper understanding of the underlying mechanism to unlock their full potential in electrolytic and environmental technologies.