| Metal oxide nanomaterials are considered as promising photocatalysts in wastewater treatment. However, there are still some problems to be solved, which could be classified as these:(1) overwide band gap;(2) lowphotocatalytic efficiency;(3) poor stability. Aiming at these problems, solvothermal methods especially hydrothermal and supercritical carbon dioxide solvohermal method, were used on sythesis of typical metal oxide semiconductor nanomaterials with specific microstructures. As follows:(1) Using supercritical carbon dioxide solvothermal method to synthesize TiO2 nanomaterials.Besides, the reaction temperature, pressure and other conditions were use to control nanostructures and photocatalytic abilities of TiO2 photocatalysts.(2) Exploring a new method to synthesize ZnO nanomaterials, combiningsupercritical sovlvothermal without additives and post heat treatment method. Besides, the morphologies transforming mechanism during heat treatment was also discussed. And hierarchical flower-like ZnO nanomaterials with high photocatalytic ability and antisepsis were obtained.(3) Using hydrothermal method to synthesize SiO2 nanosphereswith specific nanostructures. Besides, TiO2/SiO2 nanocomposites were also synthesized by hydrothermal method and post heat treatment. On this basis, the above nanomaterials were used in coatings and the transparency, hydrophobicity and photocatalytic properties of coatings were discussed.(4) Exploring new hydrothermal process with oxalic acid as additives to synthesize Ti O2/WO3 nanomaterials.Besides, the morphology evolution mechanism and the role of oxalic acid during hydrothermal process were also detailed discussed. Eventually, Anatase/Tungsten nanocomposites exhibiting high photocatalytic ability under UV/Vis were obtained. |
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