Metal-based Catalysts in Advanced Oxidation Processes (AOPs)

<jats:p>Advanced Oxidation Processes (AOPs) are water treatment methods that use reactive oxygen species (ROS), especially hydroxyl radicals (˙OH), to degrade persistent organic pollutants effectively. This chapter reviews the role of metal-based catalysts in enhancing AOPs, focusing on their synthesis, mechanisms, and applications in degrading contaminants like dyes, pharmaceuticals, and industrial chemicals. Recent advances in nanotechnology and hybrid materials have improved catalyst efficiency, stability, and reusability. However, scaling AOPs from laboratory to industrial scale presents challenges, including catalyst deactivation, cost, and environmental concerns such as metal leaching. Strategies like catalyst immobilization, green synthesis, and integration with renewable energy sources offer promising solutions to these issues. Future research directions emphasize developing sustainable, cost-effective catalysts and expanding applications to emerging pollutants. Overall, metal-based catalysts are critical for advancing AOPs toward more efficient, scalable, and environmentally friendly wastewater treatment technologies.</jats:p>