The Research Of The Synthesis And Properties Of Several Mesoporous Oxides Materials

With the advantage of large specific surface area and ordered pore structure, mesoporous materials showed extensive application prospect in photocatality, adsorption and biology. In the past few years, study on synthesis and properties of functional mesoporus materials had become an important field for researchers. This thesis devoted to fabrication and performance study of types of mesoporous nano-semiconductor photocatalytic materials. Effective methods to synthetize mesoporous materials were found. And performance of as-synthesis samples via different methods was tested. The main contents were discussed as follows:(1) Ordered nanocrystalline mesoporous BiV04 with pure phase was successfully synthesized via nanocasting using cubic MCM-48 molecular sieves as hard template. Comparing with conventional BiVO4 synthesized by hydrothermal method, the nanocasting mesoporous BiVO4 have much higher specific surface of 22.9 m2.g-1, more ordered pore structure and smaller particle size (about 10nm), which decreased the recombination of optical excitation electrons and holes efficiently. As a result, the photocatalytic efficiency of mesoporous BiVO4 for xanthate in 90 mins reached up to 78%.(2) Highly visible light active mesoporous (C,W) doped/co-doped TiO2 were synthesized via hydrothermal method by controlling the dosage of inorganic titanium sulfate, glucose and sodium tungstate. The crytal size of as-synthesized samples was about 12nm and its surface area was greater than 100 m2.g-1. Its visible light absorbance enhanced with the increasing of the W doping amounts. W6+ played the role of the electron capture agent and transferring electron that well photoresponse performance under visible light was got. The photocatalyst doped with C 1.0% and W 10% showed the highest photocatalytic activity under visible light irradiation.(3) By means of capillary force, mesoporous CuO/SiO2 composites with high surface area were triumphantly synthesized via self-assembly basing on [Cu(NH3)4]2+ into the pore of well-organized molecular sieve. The results showed that:at the ratio of Cu:Si=1:2.5, surface area and pore volume of as-synthesized host-guest materials was 219 m2.g-1 and 0.3 cm3.g-1 respectively, and it exhibited a similar bimodal pore size distribution to the host sieve, distributing extensively at about 3nm. It exhibited fine adsorption charactors with methyl blue. Simultaneously, it revealed an excellent photocatalytic activity that 92% of xanthate was degradated in 90 min.