Self-Cleaning Materials: Mechanisms, Performance and Environmental Perspectives of Photocatalytic and Superhydrophobic Surfaces

Self-cleaning materials have gained significant attention due to their potential to reduce maintenance costs, enhance durability, and promote environmental sustainability in a wide range of applications, including glass, textiles, solar panels, and medical devices. This review explores the two primary self-cleaning mechanisms: photocatalysis and superhydrophilicity. Photocatalytic materials, such as TiO₂ and ZnO, harness light energy to degrade organic pollutants, while superhydrophobic surfaces rely on extreme water repellency to remove dirt and contaminants. We discuss recent advances in material design, including nano structuring, doping, and composite formation, which have significantly improved the performance of these materials under real-world conditions. Key challenges such as mechanical durability, light dependency, toxicity of nanoparticles, and scalability are critically examined. Additionally, emerging eco-friendly strategies—like biopolymer-based coatings and safe-by-design nanostructures—are highlighted as sustainable alternatives. The review concludes with insights into future directions, including multifunctional coatings and smart integration technologies.