Photocatalytic properties, mechanical strength and durability of TiO2/cement composites prepared by a spraying method for removal of organic pollutants

Abstract

TiO₂/cement composites were prepared by a spraying method to degrade organic pollutants. After coated with waterproof liquid, pure cement pastes/mortars were sprayed with TiO₂ suspensions with different TiO₂ contents and spraying times. Photocatalytic properties, mechanical strength and durability were studied. Maximum photocatalytic activity and uniform TiO₂ distribution were achieved at the optimal conditions of 10 wt% TiO₂ content in suspension and 3 spraying times. The TiO₂/cement pastes had better degradation performance over Rhodamine B (RhB) and methylene blue (MB) than that over methyl orange (MO). After 20 times of cycling degradation, the photocatalytic efficiencies had no significant reduction. The TiO₂/cement mortars had good mechanical strengths, meeting the mechanical demands of wastewater treatment tanks. In durability, the TiO₂/cement mortars had better water penetration resistance, chloride penetration resistance and anti-carbonation than pure cement mortars.

Keywords: Durability; Organic pollutant; Photocatalytic cement; Spraying method; TiO(2).