Metal selenides have emerged as a novel class of highly efficient catalysts in advanced oxidation processes (AOPs), attributed to their distinctive characteristics, including exceptional electrical conductivity, adjustable electronic structures, and elevated catalytic activity. These materials are highly effective in producing reactive oxygen species (ROS), which are crucial for degrading persistent organic pollutants, rendering them useful in tackling environmental. The metallic characteristics of selenium and its impact on electron transfer rates distinguish metal selenides from their sulphide equivalents. Recent studies emphasize the significance of tactics including defect engineering, interface optimization, and hybridization with carbon-based materials in improving catalytic efficiency and stability. Metal selenides are gaining attention for their diverse applications, extending their utility to innovative catalytic and environmental technologies. Notwithstanding their benefits, ongoing efforts aim to address challenges related to structural integrity under extreme reaction conditions and cost-effective manufacturing techniques. This chapter discusses the synthesis, optimisation, and utilisation of metal selenides as catalysts in advanced oxidation processes (AOPs). It highlights their transformative capacity in pollutant degradation and sustainable environmental remediation, while offering insights into future strategies for improving their efficacy and incorporation into scalable water treatment systems
