Effect of Calcination Temperature on Surface Acidity and Photocatalytic Activity of Nano-TiO2/Diatomite Composite Photocatalyst

Nano-TiO 2 /diatomite composite photocatalysts were prepared by hydrolysis-deposition method in the present study. The effect of calcination temperature on surface acidity and photocatalytic activity of the photocatalysts was characterized by X-ray diffraction, N 2 adsorption/desorption, Fransmission electron microscope, Fourier transform infrared, X-ray photoelectron spectroscopy, pyridine adsorption in situ fourier transform infrared and the adsorption and photodegradation of formaldehyde in air. Results revealed that the high temperature and the nucleation of titanium dioxide both can consume the surface Brönsted acid sites, and with the formation of Ti–O–Si bond to form surface Lewis acid. The composite calcined at 600 °C presents the highest decomposition of formaldehyde under UV irradiation at the room temperature.