Synthesis Of TiO₂-based Nanosponge Composites And Their Photocatalytic Properties

Recently, the micro/nanostructural semiconductor metal oxides with a porousstructure have been widely applied in catalyst, filter, battery and sensor. Especially, theapplication in photocatalysis has aroused significant interest. Porous semiconductorwith high surface area and controllable morphologys has played a pivotal role inphotocatalysis organic and cleaning energy. Among them, TiO₂is the most potentialphotocatalyst and is capable of decomposing a wide variety of organics and inorganicsin both liquid and gas phases. However, TiO₂exist defects, such as the low utilizationrate of light, the fast recombination rate of electron-hole. Noble metal or metallic oxidedoped TiO₂has been demonstrated to be an effective approach to separate electron andhole.In this paper we take advantage of cellulose template method associated withsurface sol gel process to faithfully synthetize porous TiO₂nanosponge. Themechanism was also discussed. The composition, structure, morphology andphotocatalysis properties of the obtained products are studied. The contents aresummarized as follows：1. We take advantage of cellulose template method associated with surface sol gelprocess to synthetize TiO₂/Ag nanosponge composites. We faithfully replicate themorphological hierarchies of natural cellulosic substances, acquiring nanospongestructure. The hierarchical structures of nanosponge are mainly composed oftwo-dimension membrane features with thickness uniformity. The experimental resultsindicated the surface structure of natural cellulosic substances played important roles forthe formation of hierarchical nanosponge. A possible synthesis mechanism is proposed.The size and load capacity controlled Ag nanoparticles are deposited on the TiO₂nanosponges surface through light deposition method. Additionally, the photocatalysisproperties of composites with different Ag loading were studied systematically.2. We take advantage of cellulose template method associated with surface sol gelprocess to faithfully synthetize TiO₂/WO₃nanosponge composites. The synthesizedproducts were systematically proposed by X-ray powder diffraction （XRD）, X-rayphotoelectron spectroscopy （XPS）, field-emission scanning electron microscopy（FESEM） and transmission electron microscopy （TEM） and so on. Additionally, the photocatalysis properties of composites with different WO3loading were studiedsystematically in the visible light.