Development of Self-Cleaning Cementitious Panels with Nano-TiO₂ and Micro-ZnO: Aesthetic and Photocatalytic Impacts of Epoxy Resin Application

Abstract

Self-cleaning coatings based on nanomaterials like TiO₂ and ZnO are promising for building facades and heritage surfaces. However, their long-term effectiveness is challenged by particle loss due to rain, wind, and abrasion. Epoxy resin can potentially improve particle adhesion but may affect photocatalytic performance and visual appearance. This research aims to develop self-cleaning cement-based panels functionalized with TiO₂ and TiO₂/ZnO, and to evaluate the impact of epoxy resin on their photocatalytic activity and aesthetic properties. The photocatalytic coatings contributed to self-cleaning, promoting a significant increase in photocatalytic efficiency without causing a significant aesthetic impact on the surfaces. The application techniques, spray and dip coating, showed differences in terms of uniformity and thickness, which influenced the final performance. The use of epoxy resin preserves aesthetics but significantly compromises photocatalytic efficiency—up to 84% in some cases. Further research should explore alternative binders and surface treatments that maintain transparency and catalytic activity. These treatments should also be assessed for their long-term durability and resistance to wear.