Photocatalytic degradation of particulate pollutants and self-cleaning performance of TiO2-containing silicate coating and mortar

• Photocatalytic materials remove particulate pollutant and self-clean building surface.
• 15% TiO2 by mass of solid silicate is determined as an optimal dose of the coating.
• Silicate coating with 15% TiO2 has performance comparable to mortar with 2% TiO2.
• Silicate coating with 15% TiO2 requires much less TiO2 than mortar with 2% TiO2.
• Silicate coating with TiO2 shows satisfactory durable photocatalytic efficiency.

Photocatalytic degradation of particulate pollutants and self-cleaning performance of TiO2-containing silicate coatings and TiO2-containing mortars were experimentally examined and compared using rhodamine B (RhB) as a surrogate for airborne particulate pollutants. An optimal dosage of the TiO2 in the silicate coating was determined from the experiments. The specimens coated with silicate containing 15% TiO2 by mass of solid silicate had photocatalytic performance comparable to the mortar specimens with 2% TiO2 by mass of cement although the former required 20 times less TiO2 (based on 12 mm thick specimens). The specimens coated with silicate containing 15% TiO2 showed satisfactory degradation efficiency in laboratory accelerated tests up to 2500 h of simulated UV irradiation, similar to at least 2.4 years based on a tropical warm and humid condition, indicating its durable performance.