Photocatalytic reduction of NO with NH 3 using Si-doped TiO 2 prepared by hydrothermal method

Abstract

A series of Si-doped TiO 2 (Si/TiO 2) photocatalysts supported on woven glass fabric were prepared by hydrothermal method for photocatalytic reduction of NO with NH 3. The photocatalytic activity tests were carried out in a continuous Pyrex reactor with the flow rate of 2000 mL/min under UV irradiation (luminous flux: 1.1 × 10 4 lm, irradiated catalyst area: 160 cm 2). The photocatalysts were characterized by X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectrophotometer, transmission electron microscopy (TEM), photoluminescence (PL) and temperature-programmed desorption (TPD). The experiment results showed that NO conversion on Si/TiO 2 at 323 K could exceed 60%, which was about 50% higher than that on Degussa P25 and pure TiO 2. With the doping of Si, photocatalysts with smaller crystal size, larger surface area and larger pore volume were obtained. It was also found that Ti–O–Si bands were formed on the surface of Si/TiO 2 and that the surface hydroxyl concentration was greatly increased. As a result, total acidity and NH 3 chemisorption amount were enhanced for Si/TiO 2 leading to its photocatalytic activity improvement.