Study on Photocatalytic Performance of Ag/TiO2 Modified Cement Mortar.

ABSTRACT

In this paper, Ag-TiO2 photocatalysts with different Ag contents (1 mol%-5 mol%) were prepared and applied to cement mortar. The photocatalytic performance of Ag-TiO2 and photocatalytic cement mortar under UV light and simulated solar light was evaluated. The results showed that Ag loading on the surface of TiO2 could reduce its band gap width and increase its absorbance in the visible region, and 2% Ag-TiO2 had the highest photocatalytic activity under UV light, the degradation rate of methyl orange (MO) was 95.5% at 30 min, and the first-order reaction constant k was 0.0980 min-1, which was 61.7% higher than that of TiO2, and 5% Ag-TiO2 had the highest photocatalytic activity under solar light, the degradation rate of methylene blue (MB) was 69.8% at 40 min, and the first-order reaction constant k was 0.0294 min-1, which was 90.9% higher than that of TiO2. The photocatalytic mortar prepared by the spraying method has high photocatalytic performance, The MO degradation rate of sample S2 under UV light was 87.5% after 120 min, MB degradation rate of sample S5 under solar light was 75.4% after 120 min. The photocatalytic reaction conforms to the zero-order reaction kinetics, which was 1.5 times-3.3 times higher than that of the mixed samples and has no effect on the mechanical properties of mortar.