High-Performance Surface-Modified Metal Oxide Nanostructures for Efficient Organic Pollutant Removal and CO₂ Conversion

Environmental pollution caused by organic contaminants and rising atmospheric CO₂ has emerged as a critical global issue. Metal oxide nanoparticles, including TiO₂, ZnO, Fe₂O₃, CuO, and CeO₂, have attracted significant attention due to their unique physicochemical properties, high surface area, tunable band gaps, and strong photocatalytic activity. These nanomaterials can efficiently degrade organic pollutants such as dyes, phenols, pharmaceuticals, and pesticides, while simultaneously facilitating the conversion of CO₂ into useful fuels like methane, methanol, and formic acid. Green synthesis methods, using plant extracts, bacteria, fungi, and algae, provide an eco-friendly and sustainable approach to nanoparticle production. Surface modification strategies, including metal/non-metal doping, heterojunction formation, and functionalization, enhance light absorption, charge separation, and catalytic performance. This review presents a comprehensive discussion on the synthesis, characterization, and surface engineering of metal oxide nanoparticles, highlighting their roles in environmental remediation and CO₂ conversion. The paper also identifies challenges and future directions for the development of efficient, sustainable, and cost-effective nanomaterials for pollution control and carbon management