The Study Of Preparation And Photocatalytic Of Compound Nanomaterials TiO₂/SnO₂

TiO₂ photocatalyst is one of the most promising environmentally friendly photocatalysts, and current issues of this photocatalyst study include expanding its range of light absorption and improving the quantum efficiency. TiO₂ mixed with semiconductor such as SnO₂ whose conduction and valence band match with TiO₂ can improve the quantum efficiency. In this paper, the morphology and structure of composite TiO₂/SnO₂ prepared by sol-hydrotheral crystallization were characterized by XRD and SEM. The catalytic activity of TiO₂/SnO₂ prepared under different conditions (moment of adding SnO₂ (t_p-c), hydrotheral crystallization time and the ratio of W_TiO2/W_SnO2) was judged by the ability of removing toluene gas.This paper discussed the relationship bewteen preparation conditions (temperature, H₂O/TNB ratio, and the amount of inhibitor) and the properties of TiO₂ sol. The effects of t_p-c , crystallization time and the ratio of W_TiO2/W_SnO2 on the crystal structure of TiO₂ in TiO₂/SnO₂ and the photocatalytic activity of compound TiO₂/SnO₂ particles were also investigated. The results were showed as follows.The concentration of the sol particle increased as the hydrolysis temperature or H₂O/TNB ratio was raised, and the particle size increased with both the H₂O/TNB ratio and the amount of inhibitor. It was also found that the gelation time rapidly decreased with both the temperature and the H₂O/TNB ratio, but increased as the amount of the inhibitor (acetic acid) increased. Increasing the volume of the inhibitor not only increased the gelation time, but also changed the crystal structure of TiO₂ gel.The structure of TiO₂ in TiO₂/SnO₂ and the coated quality is closely related to t_p-c. The peaks intensities of anatase TiO₂ in the obtained compounds TiO₂/SnO₂ particles were much weaker as the t_p-c increased. No TiO₂ coated on the surface of SnO₂ When t_p-c is 60 min. The photocatalytic activity of the composite samples increased and then decreased with t_p-c increased. The compound samples have the highest degradation rate of toluene when t_p-c is 45 min.With the increase of the crystallization time and the ratio of W_TiO2/W_SnO2, the crystal structure of anatase-TiO₂ in the compound TiO₂/SnO₂ particles became completely and the degradation rate of toluene increased. However, degradation rate of toluene had no significant provement with the ratio of WTiO₂/WSnO₂ increased to 0.70.