Abstract:

Two low temperature synthesized nano-TiO2 hydrosols and two commercial nano-TiO2 powders (5 nm and 30 nm) were used to prepare four different nano-TiO2 loaded cotton fabrics using pad-dry process, respectively. After XRD and SEM characterizing, their photocatalytic performance were then evaluated and compared in the degradation of Acid Red 88. The results indicated that four nano-TiO2 were characterized to be anatase type. However, the nano-TiO2 particles in the hydrosols were imperfect crystals. The films of two nano-TiO2 hydrosols and a nano-TiO2 powder with 5 nm size formed on the surface of cotton fabrics showed the similar morphology, which was significantly different from that of nano-TiO2 powder with 30 nm size formed on the surface of cotton fabric. Moreover, the photocatalytic performance of two nano-TiO2 hydrosols and a nano-TiO2 powder with 5 nm size loaded cotton fabrics were higher than that of nano-TiO2 powder with 30 nm size loaded cotton fabric in acidic and neutral medium. But, two nano-TiO2 powder loaded cotton fabrics had better catalytic activity than the nano-TiO2 hydrosol loaded cotton fabrics in alkaline medium. In addition, nano-TiO2 powder with 30 nm size loaded cotton fabric exhibited the reduced photocatalytic performance than other three nano-TiO2 loading cotton fabrics under visible irradiation. Better photocatalytic performance was found for two nano-TiO2 powder loaded cotton fabrics in the presence of NaCl or SDBS.