Photocatalytic H2 Evolution from Glycerol Solution over Bi3+-doped TiO2 Nanoparticles

TiO2 and Bi3+-doped TiO2 semiconductors were prepared by using Sol-Gel method. Their pore size distribution, crystal structure, surface composition, photo absorption properties and photocatalytic performance for H2 evolution from glycerol solution were investigated by techniques of N2 adsorption-desorption, XRD, FT-Raman, SEM, UV-Vis DRS and photocatalytic reaction. The results show that Bi3+-doped TiO2 appears anatase phase nanoparticles with mesoporous structure and has a much smaller crystallite size and much higher BET surface area than bare TiO2. These samples exhibit a visible-light absorption capability much higher than bare TiO2, which mainly originates from the doping process with the formation of new energy level of Bi3+ between conduction band and valence band of TiO2 to reduce the energy gap and the electron–hole recombination rate. The Bi3+-doped TiO2 samples display improved photocatalytic H2 production from glycerol solution, and 2%Bi-doped TiO2 shows a maximum H2 production rate of 3534.8 μmol/(h·gcat) under UV irradiation and 455.7 μmol/(h·gcat) under simulated-solar irradiation, respectively.