Photocatalytic Metal Oxide-Based Nanocomposites for Environmental Decontamination and Pollution Abatement: A Comprehensive Review

The rapid growth of industrialization, urbanization, and agricultural activities has resulted in the large-scale release of hazardous organic and inorganic pollutants into the environment, posing serious risks to ecosystems and human health. Among various advanced treatment technologies, photocatalysis based on metal oxide–derived nanocomposites has emerged as an efficient and environmentally benign strategy for environmental decontamination and pollution abatement. Compared to singlecomponent photocatalysts, metal oxide–based nanocomposites exhibit superior photocatalytic activity due to enhanced charge separation, extended light absorption range, and improved surface redox reactions. This comprehensivereview critically discusses recent advances in the design, synthesis, characterization, and photocatalytic applications of metal oxide–based nanocomposites for the removal of dyes, pharmaceuticals, pesticides, and other emerging contaminants from water and air. The role of heterojunction engineering, defectmodulation, morphology control, and reaction mechanisms is systematically analyzed. Furthermore, current challenges, scalability issues, and future perspectives for practical environmental applications are highlighted. This review aims to provide a consolidated platform for researchers to develop next-generationphotocatalysts for effective pollution control.