The X ray diffraction XRD patterns were obtained on a

The morphology of TiO2 powders were observed using a transmission agenerase microscope (TEM) (Tecnai G20, USA) with an acceleration voltage of 200 kV and a field emission scanning electron microscope (SEM) (S-4800, Hitachi, Japan) with an acceleration voltage of 10 kV, respectively. Nitrogen adsorption-desorption isotherms were collected on an ASAP 2020 (Micromeritic Instruments, USA) nitrogen adsorption apparatus after the samples had been degassed at 150 °C. The BET specific surface area (SBET) was determined by a phylum multipoint BET method using the adsorption data in the relative pressure p/p0 range of 0.05–0.30.