Study on preparation of modified nano-TiO_2 and its application in photocatalytic treatment wastewater containing Cd~(2+)

摘要

Nano-Sn_(0.25)Ti_(0.75)O_2 was prepared with hydrothermal method using tetrabutyl titanate as one of the primary raw materials. The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn~(4+)-doped nano-TiO_2 is rutile, and the nanoparticles diameter was 14.49nm. Photocatalytic treatment the machining wastewater containing cadmium ions with the UV excitation by Nano-Sn_(0.25)Ti_(0.75)O_2 was investigated. The experimental results show that Nano-Sn_(0.25)Ti_(0.75)O_2 can be used as photocatalyst to removal Cd~(2+) from the wastewater effectively with the UV excitation. The wastewater pH value, the initial concentration of Cd~(2+), the amount of catalyst, the reaction time and other factors affect the efficiency of photocatalytic treatment significantly. The optimization experimental conditions for photocatalytic treatment wastewater containing cadmium ions are as follows, when the concentration of Cd~(2+) in the wastewater is 20mg/L, amount of Sn_(0.25)Ti_(0.75)O_2 is 2g/L, pH in wastewater is 7 and the photocatalytic reaction time is 2h, the removal rate of Cd~(2+) from the wastewater is up to 98.4%.