Mesoporous TiO 2 with wormlike structure synthesized via interfacial surfactant assisted route

Abstract

A novel route to prepare mesoporous TiO 2 with wormlike structure is developed via hydrolysis of titanium isopropoxide (TIP) with the surfactant (EO) 20–(PPO) 70–(EO) 20 (P123) and with the aid of supercritical (SC) CO 2 at the interface of SC CO 2 and an aqueous solution. Our experimental results demonstrate that the surfactant P123 and SC CO 2 play an important role in synthesizing mesoporous TiO 2 because the surfactant P123 can take up directing function and SC CO 2 can reduce the TIP hydrolysis reaction rate, both of which are in favor of preparing mesoporous TiO 2. The resultant TiO 2 products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen sorption measurements. Nitrogen analysis reveals that the mesoporous TiO 2 presents high surface area ( a s) of 494.2 cm 2/g in comparison with the TiO 2 particles ( a s = 202.4 m 2/g) and microspheres ( a s = 28.6 m 2/g) obtained in our work. Furthermore, the mesoporous TiO 2 exhibits a considerably high photocatalytic oxidation of 2-propanol applying a 200-W high-pressure Hg lamp (340 nm) as irradiation due to its high surface area.