石墨烯/纳米TiO2复合材料的制备及其光催化性能

以氧化石墨烯（GO）和钛酸四丁酯（Ti（OBu）₄）作为初始反应物，采用乙醇溶剂热法合成了石墨烯/纳米TiO₂复合材料，并利用XRD、FE-SEM、TEM、RAMAN和XPS等手段对石墨烯/纳米TiO₂复合材料的晶体结构、形貌及元素形态等性质进行了表征，同时将复合材料应用于光催化降解甲基橙溶液，进行光催化性能评价。结果表明：Ti（OBu）₄在乙醇溶剂中通过化学静电引力吸附到GO表面，经过溶剂热反应，GO被还原成石墨烯的同时，石墨烯的表面负载生长锐钛矿TiO₂颗粒。随着溶剂热反应时间的延长，GO表面的活性基团减少，还原更加彻底，同时TiO₂晶粒有一定的增大趋势；与纯TiO₂相比，石墨烯/纳米TiO₂复合材料光催化活性明显提高，石墨烯含量对复合材料的光催化活性有直接的影响。

Preparation and photocatalytic activity of graphene/nano TiO2 composites

Using graphene oxide (GO) and tetrabutyl orthotitanate (Ti(OBu)₄) as raw materials, the graphene/nano TiO₂ composites were synthesized via a solvothermal reaction in ethanol solvent. The crystal structure, morphology and element form of graphene/nano TiO₂ composites were characterized by XRD, FE-SEM, TEM, RAMAN and XPS. And the photocatalytic activity of graphene/nanoTiO₂ composites was investigated by the photocatalytic degradation of methyl orange in aqueous solution. The results show that Ti(OBu)₄ molecules are uniformly grafted on GO by chemisorption in ethanol solvent, both of the reduction of GO and deposition of anatase TiO₂ nanoparticles on GO are achieved during the solvothermal process. With prolongation of solvothermal reaction, the content of active groups on GO quickly decreases, so GO is reduced more firmly. Meanwhile, the size of TiO₂ crystal particles increases with the prolongation of solvothermal reaction. Compared to pure TiO₂, the graphene/nano TiO₂ composites exhibit higher photocatalytic activity, and the graphene ratios in composites have direct impact on the photocatalytic activity.