Photocatalytic Hydrogen Production Catalyzed By Copper-titanium Composite Oxides

Photo catalytic H2production from water is a promising system to produce a sustainable and clean energy source and thus becomes a hot research topic.TiO2has been widely studied as photocatalysts for a variety of photo catalytic reactions because of its non-toxic, inexpensive and chemically stable advantages;however, it’s wide bandgap and narrow range of light absorption limited to the UV light region strongly limit its industrial applications. Modifications of TiO2by various strategies are effective in promoting its photocatalytic activity. In this thesis, the preparation, structures and photocatalytic activities of CuOx-TiO2composite oxide photocatalysts have been comprehensively studied, including:1. CuOx-TiO2composite oxide was prepared by the liquid-solid interfacial redox reaction between TiCl3and Cu(OH)2solids. The as-synthesized composite oxide experiences an induction period during the photocatalytic H2production reaction from water under the simulated solar light irradiation. No photocatalytic activity was observed in the initial5hours but then a stable photocatalytic activity appeared. Structural characterization results reveal that the TiO2-CuO heterojunction exposed on the as-synthesized composite oxide gets photo-reduced into the TiO2-Cu2O heterojunction during the induction period. These results give solid experimental evidence that the active Cu component in CuOx-TiO2composite oxide photocatalysts is Cu2O, instead of CuO.2. TiO2with different phase compositions were prepared by the hydrothermal treating of titanate nanotubes in the HNO3aqueous solutions with different HNO3concentrations and employed as the support to prepare Cu2O/TiO2photocatalysts by impregnation. It was found that the photocatalytic activity order of acquired Cu2O/TiO2photocatalysts is different from that of the TiO2support. H2-TPR profiles demonstrate different Cu2O-TiO2interactions in Cu2O/TiO2photocatalysts with different TiO2phase compositions. These results demonstrate that the synergetic promotion effect of heterojunctions and phase-junctions on the photocatalytic activity is not a simple addition of the individuals...