Abstract

The development of self-cleaning surfaces is crucial for reducing maintenance costs, conserving energy, and minimizing detergent use across various applications, including construction, healthcare, and consumer electronics. In this study, we introduce a novel glass surface with self-cleaning properties under visible light based on the photocatalytic activity of immobilized BiOI/TiO₂ heterostructures. The BiOI/TiO₂ heterostructures were synthesized, characterized, and immobilized on glass slides to evaluate their photocatalytic and self-cleaning efficiencies under simulated solar conditions. Among the synthesized heterostructures, the BiOI(0.1)/TiO₂(0.9) heterostructure leverages an S-scheme charge transfer mechanism, significantly enhancing charge separation efficiency and hydroxyl radical generation under simulated solar conditions. This structure results in enhanced photocatalytic activity compared to pure TiO₂ and BiOI, as evidenced by improved methyl orange degradation and self-cleaning performance. Self-cleaning tests based on ISO 27,448:2009 showed that the glass surface with immobilized BiOI(0.1)/TiO₂(0.9) significantly outperforms glass surfaces with immobilized nanoparticles of pure TiO₂ and pure BiOI, reducing water contact angles faster and enabling surface cleanliness with minimal irradiation. These findings highlight the BiOI(0.1)/TiO₂(0.9) heterostructure as a high-efficiency photocatalyst with potential application in self-cleaning coating opening pathways for next-generation energy-efficient antimicrobial surfaces in real-world applications. © 2025