Advances in Zinc Oxide nanomaterials and nanocomposites for photocatalytic and biomedical applications

This review comprehensively explores the synthesis, doping, and applications of zinc oxide (ZnO) nanomaterials and their composites. Various synthesis strategies, including hydrothermal, sol-gel, precipitation, and green methods, are discussed with emphasis on their influence on ZnO’s size, morphology, and optical properties. The role of doping—transition metals, lanthanides, and non-metals—enhancing ZnO’s electronic and photocatalytic performance is highlighted, particularly for visible light absorption and electron-hole pair separation. ZnO-based nanocomposites with metal oxides, carbon, and spinels exhibit synergistic properties, addressing challenges like photo-corrosion and expanding applications in environmental remediation, and photocatalysis. ZnO’s antibacterial efficacy and its integration into medical, textile, and industrial fields underscore its versatility. The review identifies future prospects in improving scalability, structural defect control, and standardized characterization for emerging technologies. This study consolidates the advancements in ZnO research, offering insights for material scientists and engineers to optimize ZnO-based materials for sustainable applications.