Photocatalytic Performance and Kinetic Studies of a Wood Surface Loaded with Bi₂O₃-Doped Silicon-Titanium Composite...

In this paper, a surface self-cleaning wood was obtained by loading Bi₂O₃-doped silica-titanium composite film on the surface of wood by the sol-gel method. The effects of different Bi doping amounts on the structure and photocatalytic properties of the modified wood were investigated. The doping of Bi₂O₃ inhibited the growth of TiO₂ crystals and the phase transition from anatase to rutile. In addition, Bi₂O₃ could improve the photocatalytic activity of the composite film by appropriately reducing the grain size of TiO₂ and increasing the crystallinity of TiO₂. Furthermore, doping with Bi₂O₃ shifted the absorption wavelength of the wood samples back into the visible range, indicating that the increase in Bi content favoured light absorption. The wood samples loaded with Bi₂O₃-doped Si-Ti composite membranes had the best photocatalytic activity and the highest reaction rate when n (Ti):n (Bi) = 1:0.015. Degradation rates of 96.0% and 94.0% could be achieved for rhodamine B and gaseous formaldehyde, respectively. It can be seen that wood samples loaded with Bi₂O₃-doped Si-Ti composite films on the surface exhibit excellent photocatalytic activity against both gaseous and liquid pollutants.