Photocatalytic Degradation of Organic Pollutants using Metal Oxide Nanoparticles

Abstract

The increasing contamination of water bodies with persistent organic pollutants has intensified interest in sustainable remediation techniques. Photocatalysis—leveraging metal oxide nanoparticles activated by light—offers a promising pathway to degrade dyes, pharmaceuticals, and industrial organics efficiently. This study explores the design, synthesis, and photocatalytic performance of several metal oxide nanoparticles—such as ZnO, SnO₂ (in rGO-SnO₂ composites), and ZnO/NiFe₂O₄—for organic pollutant degradation under UV and natural sunlight. ZnO/NiFe₂O₄ nanocomposite, synthesized via solid-state calcination of green-synthesized ZnO and NiFe₂O₄ at 850 °C for 10 h, demonstrated high degradation efficacy against methylene blue under UV light, primarily driven by hydroxyl radicals and photogenerated holes arXiv. The rGO-SnO₂ nanocomposite produced via solution mixing showed remarkable photodegradation (~94–95%) of methylene blue within 15 minutes under UV and natural sunlight arXiv. Additional research from the literature reveals broad applicability of metal oxide-based nanoparticles—particularly ZnO, TiO₂, CuO, Co₃O₄, and spinel ferrites—for pollutant remediation, benefiting from their tunable morphology, bandgap, high surface area, and green synthesis feasibility Overall, these metal oxide nanoparticles deliver high degradation efficiencies, rapid kinetics, and, in some cases, magnetic recoverability—highlighting their potential for real-world water treatment. Future directions include exploring doping, composite formation, visible-light activation, robust reusability, and scalable green synthesis strategies.