Fast Sol–Gel Method to Prepare Mesoporous TiO2 with High Photocatalytic Activity

Mesoporous TiO 2 nanoparticles were synthesized via a fast and classical sol–gel method, respectively. Polyacrylamide was used as the template in the fast sol–gel route; the polymerization crosslink by hydrogen bonds between the template and hydrolysates of Ti alkoxides shortens the reaction time from several days to several hours. The X-ray diffraction results testified that only anatase was obtained in the samples, and the crystallite sizes of the samples prepared by fast and classical sol–gel method were 13.6 nm and 20 nm, respectively. Transmission electron microscopy and N 2 adsorption–desorption reveal that the nanocrystals have typical mesoporous structure and high surface areas. The pore sizes and surface areas of the samples prepared by fast and classical sol–gel method are 17.3 nm and 28.2 nm, 154.7 m 2 /g and 102.6 m 2 /g, respectively. The photocatalytic degradation of methyl orange solution under UV light irradiation suggests that the mesoporous TiO 2 photocatalyst prepared by the fast sol–gel method exhibits higher photocatalytic activity than the mesoporous TiO 2 prepared via classical sol–gel method.