**A. Rosales 1, A. Maury-Ramírez 2, R. Mejía-De Gutiérrez 3, C. Guzmán <sup>1</sup> and K. Esquivel 1,\***


Received: 2 February 2018; Accepted: 19 March 2018; Published: 24 March 2018

**Abstract:** Use of silicon dioxide (SiO2) and titanium dioxide (TiO2) have been widely investigated individually in coatings technology, but their combined properties promote compatibility for different innovative applications. For example, the photocatalytic properties of TiO2 coatings, when exposed to UV light, have interesting environmental applications, such as air purification, self-cleaning and antibacterial properties. However, as reported in different pilot projects, serious durability problems, associated with the adhesion between the substrate and TiO2, have been evidenced. Thus, the aim of this work is to synthesize SiO2 together with TiO2 to increase the durability of the photocatalytic coating without affecting its photocatalytic potential. Therefore, synthesis using sonochemistry, synthesis without sonochemistry, physical characterization, photocatalytic evaluation, and durability of the SiO2, SiO2@TiO2 and TiO2 coatings are presented. Results indicate that using SiO2 improved the durability of the TiO2 coating without affecting its photocatalytic properties. Thus, this novel SiO2@TiO2 coating shows potential for developing long-lasting, self-cleaning and air-purifying construction materials.

**Keywords:** hydrophobic; photocatalytic; sonochemistry; coating; mortar
