Towards Sustainable Photocatalytic Degradation of Organic Pollutants through Rational Design of Engineered Magnetically Retrievable Metal Oxide@Graphene Oxide Nanocomposites

Abstract

Toxic pollutants in aqueous media cause great harm to both the environment and living beings, thus, the remediation of such pollutants through the design and development of highly efficient and recyclable nanomaterials is pivotal. These nanoscale platforms enable superior adsorption and catalytic performance while minimizing energy input and secondary waste compared to conventional treatment technologies. Among the various nanomaterials investigated, magnetically retrievable graphene oxide nanocomposites have emerged as highly promising candidates for the remediation of a large array of pollutants, including heavy metals and organic contaminants such as dyes, pesticides, herbicides, and pharmaceuticals. The outstanding performance of such nanocomposites is attributed to their high specific surface area, which enables increased adsorption capacity, superior degradation efficiency, excellent stability, ease of magnetic separation, facile modification and functionalization,. Furthermore, recent studies have demonstrated that coupling semiconducting metal oxides with graphene oxide-based nanocomposites yields photoactive materials with tailored band gaps, capable of harnessing solar or visible light for photocatalytic degradation, thereby providing an affordable, efficient, and sustainable strategy for treating air and water contamination. This review examines the synthesis and functionalization of such nanomaterials, with particular emphasis on their photocatalytic pollutant removal mechanisms. By integrating mechanistic insights with applicationoriented considerations, this work offers a cohesive framework for the rational design of sustainable, reusable, and efficient nanomaterials for environmental remediation and water purification. In doing so, it bridges fragmented research efforts, highlights future research directions, and provides actionable insights for translating laboratory innovations into real-world environmental remediation solutions.