Preparation of silicon-doped TiO 2 fiber and supported TiO 2 and comparison study of their photocatalytic activity

The Si-doped TiO 2 fiber and supported TiO 2 were prepared by sol–gel method and steam heat treatment, by using titanic chloride (TiCl 4 ) as titanium source, tetraethoxysilane as silicon source and alumina foam ceramic as carrier. The samples were characterized by X-ray diffraction, scanning electron microscope, and ultraviolet–visible spectrophotometer. Methyl orange solution (with a concentration of 20 mg/l) was chosen for photodegradation. The influences of calcination temperature, dopant concentration and solution pH value on the decolorization efficiency of methyl orange were studied systematically. The photoactivity of TiO 2 fiber and supported TiO 2 were also compared. The results showed that the optimal conditions for preparing the anatase TiO 2 with good photocatalytic activity was: calcination temperature 700 °C, calcination time 2 h, Si doping amount 20 mol%. Si-doped TiO 2 fiber and supported TiO 2 exhibited high photocatalytic efficiency on the degradation of methyl orange solutions in condition of strong acid (pH = 2) and strong alkaline (pH = 13.5). TiO 2 fiber and supported TiO 2 are easy to be separated and reused in water treatment, so they have high practical value. Graphical abstract