Advancements in self-cleaning building materials: Photocatalysts, superhydrophobic surfaces, and biocides approaches

In recent years, there has been a growing interest in developing self-cleaning materials, with the civil construction sector embracing this trend. Titanium oxide (TiO2) has emerged as the most studied material for this purpose due to its affordability and non-toxic nature. However, controversies surrounding its use, such as low absorption of visible light and agglomeration in alkaline environments, have prompted exploration for alternatives. Therefore, this article aims to introduce novel approaches to achieving self-cleaning building materials. Moreover, this review endeavors to broaden the understanding of self-cleaning materials, extending the understanding of self-cleaning to antimicrobial and air-purifying properties, besides the self-cleaning property itself. Additionally, it explores solutions beyond photocatalysts, delving into the literature on superhydrophobic materials and other biocides capable of fulfilling the self-cleaning function. Finally, the challenges associated with the utilization of such materials are also addressed.