The Preparation And Photocatalytic Property Of Nanosheet And Spherical Titania With Graphene Composites

As we all know, titania can use to decompose the very stable, toxic, and harmfulpollutants under the UV light irradiation. Also owing to its cheapness, non-toxic, anddoesn’t cause secondary pollution, titania has been the most widely used to explore andresearch. In order to improve the performance of photocatalytic degradation, previousstudies mainly concentrated in:1. exposure the001high-energy surfaces of anatasetitania;2. coupled semiconductor as WO3etc;3. deposit metal as Au, Ag etc;4. dopedwith metal or nonmetal modification;5. applications of organic or inorganic molecularsurface sensitization, etc. And these work mainly focused on restricting the combinationof holes and electrons produced by optical excitation. However, in a light catalyticreaction process, the adsorption of catalyst to target substance degraded is an importantfactor, too. The graphene raised in recent years has a good property in conductive andadsorption etc. Researchers have paid great attention to graphene titania composite andalso got a lot of research results. In this paper, the graphene titania composite was usedas research object. We designed to take the varied structure from nanosheets to microspherical titania compound with doped graphene with oxygen (GO) or nitrogen (NGs)separately. We also characterized and researched the structure and photocatalyticproperty of the composites. From the result of the experiment, we can see that the betterthe titania compound with graphene, the better the electron could conduct by graphenefor a good photocatalytic property. We mainly do some works in these several aspectsfollowing:(1) We used the cheap raw materials graphite powder, concentrated sulfuric acid,concentrated nitric acid, potassium permanganate, hydrogen peroxide solution andconcentrated ammonia to prepare mild oxygen doped graphene, deep oxygen dopedgraphene and nitrogen doped graphene. We also characterized their morphology andstructure by SEM, TEM, XRD, XPS, IR etc.(2) We prepared nanoparticle and microspherical titania with tetrabutyl titanate,acetic acid and hydrogen peroxide; also we got microspherical titania by oxygentitanium sulfate, urea and ammonium fluoride. The titania graphene composites wereobtained from the reaction of TiO2and GO. The TiO2prepared are all anatase typestructure, well crystallization, compounded with graphene significantly, also it was veryimportant to use concentrated sulfuric acid to dispose the catalyst. Their photocatalyticperformance is studied, too. The results show that the photocatalytic performance could be improved by control the ratio of graphene between titanium.(3) The titania nitrogen doped graphene composites were prepared by TiO2withnitrogen doped graphene. We also characterized the composites by SEM, TEM, XRD,XPS, IR, etc. In the research of photocatalytic performance, we got our expected aimowing to the nitrogen atom doped into the graphene. In the process of reaction onlyused hydrothermal method, it showed that the property of graphene could be enhancedby nitrogen atom doped into the graphene carbon layer.