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Bi-doped TiO 2 nanotubes with variable Bi/Ti ratios were synthesized by hydrothermal treatment in 10 mol•L -1 NaOH (aq.) through using Bi-doped TiO 2 particles derived from conventional sol-gel method as starting materials. The effects of Bi content on the morphology, textural properties, photo absorption and photocatalytic activity of TiO 2 nanotubes were investigated. The scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) observations of the obtained samples revealed the formation of titanate nanotube structure doped with Bi, which exists as a higher oxidation state than Bi 3＋ . Bi-doping TiO 2 nanotubes exhibited an extension of light absorption into the visible region and improved photocatalytic activities for hydrogen production from a glycerol/water mixed solution as compared with pure TiO 2 nanotubes. There was an optimal Bi-doped content for the photocatalytic hydrogen production, and high content of Bi would retard the phase transition of titanate to anatase and result in morphology change from nanotube to nanobelt, which in turn decreases the photocatlytic activity for hydrogen evolution.

A series of sulfide coupled semiconductors supported on SiO2, (), was prepared by incipient wet impregnation method. The photocatalysts were characterized by XRD, XPS, TPR, and UV/Vis DRS. Characterization results show that the chemical actions between ZnS and CdS resulted in the formation of solid solutions on the surface of the support and the formation of them is affected by the molar ratio of ZnS/CdS and calcination temperature. Performance of photocatalysts was tested in the home made reactor under both UV light and solar-simulated light irradiation by detecting the rate of the photocatalytic H2evolution from glycerol solution. The hydrogen production rates are related to the catalyst composition, surface structure, photoabsorption property, as well as the amount of solid solution. The maximum rate of hydrogen production, 550 μmol·h−1under UV light irradiation and 210 μmol·h−1under solar-simulated light irradiation, was obtained over Cd0.8Zn0.2S/SiO2solid solution calcined at 723 K.

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