The hierarchical porous structure of substrate enhanced photocatalytic activity of TiO2/cementitious materials

Although the use of TiO2 photocatalyst on cementitious materials for air purification has been developing rapidly in the last decades, the photocatalytic effect of TiO2 is significantly diminished due to the low specific surface areas, poor gas diffusion and light transmission performance of cementitious substrates. This paper presents a novel hierarchical porous structure magnesium cementitious/TiO2 photocatalyst (FMOC/TiO2) to improve the photocatalytic effect and utilization rate of TiO2 in cementitious materials. The results revealed that the hierarchical porous structure of substrate was beneficial to the dispersion of TiO2, which provided more active TiO2 sites and large catalytic areas. The good gas diffusion and light transmittance performance of substrate improved the photocatalytic effect and utilization rate of TiO2 particles. The reaction rate of gaseous acetone in FMOC/T12 (∅50 * 3 mm) surface was measured to be about 3.87 times higher than MOC/T12 (∅50 * 3 mm). Additionally, FMOC/T12 (∅50 * 3 mm) also exhibited an excellent re-use performance.