| 초록 |
TiO2 thin-films of several micrometers prepared on concrete substrates suffer from abrasion which leads to erosion as rain washes down the coated surfaces. In this study, photocatalytic stability of TiO2 coatings was investigated on mortar-mixed-TiO2-sol, mortar-mixed-TiO2-sol with TiO2-sol coating in comparison with only TiO2 coated concrete substrates. Concrete mortar substrates of 3.5 ˟ 3.5 ˟ 0.5 cm were calcined at 450°C and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and UV-vis spectrometer. The photocatalytic properties were determined by degradation of methylene blue under 254 nm light. The reusability studies of the TiO2 coupled concrete composites was evaluated by repeating photocatalytic tests after subsequent washing and drying process. The 3-cycle photoactivity of the bare concrete coated with TiO2, mortar-mixed-TiO2 concrete without and with TiO2 coating showed preserved photoactivity with respect to the 1st-cycle photoactivity. The mortar-mixed-TiO2 coated with TiO2 showed the most stable photocatalytic activity. Therefore, for long-term photocatalytic activity and durability of coating layer, the mortar-mixed-TiO2 coated with TiO2 is a possible alternative for preventing loss of TiO2 on concrete surfaces. |
