Study On The Preparation And High Catalytic Performance Of TiO₂/Graphene Composites

The excellent photocatalytic property of nano TiO2is well known, but it also has its own deficiencies. To further improve the photocatalytic performance of TiO2, it is not only to find the breakthrough from the TiO2itself, but also to find the synergy effect of TiO2combined with other materials. Herein, not only the enhancement in the photocatalysis of TiO2has been realized by itself, also high photocatalytic performances of TiO2composites have been achieved with the help of its combination of graphene. The main research contents in this thesis are as follows:1. Graphene oxide is prepared by a modified Hummer’s method. It is reduced to graphene as a matrix for loading TiO2crystals during the combination process. The synergistic effect between TiO2crystals and graphene leads to a great enhancement in the photocatalytic performance of the composites.2Graphene-wrapped TiO2sphere composites have been synthesized by the hydrothermal method. The UV-photocatalytic performances of the as-prepared products before and after calcination are compared. The result shows that there is no significant difference from each other. Both of them exhibit the great degradation of methyl orange efficiency under the UV-light.3TiO2/graphene composites with high-energy{001} face are prepared by the hydrothermal method, and characterized using TEM, XRD, Raman, XPS and TG. The UV-photocatalytic performances of the as-prepared products before and after calcination have been compared by means of the UV-photocatalytic degradation of methyl orange solution. TiO2/graphene composites from different graphene oxides produced by different methods have been synthesized. It is found that the preparation method of graphene oxide does not influence the crystallization process and growth orientation of TiO2crystals. In order to prepare TiO2crystals with high-energy{001} faces via a green method, NaF is used to substitute HF as the growth director. The resulting product of TiO2/graphene shows prism shape. Due to the different effects of NaF and HF on the growth of crystal facets, the product shows a poor photocatalytic performance under UV-light, compared to that of TiO2/graphene produced with HF.