金红石相TiO2-石墨烯复合材料的制备及其光催化性能

以鳞片石墨为原料, 用改进的Hummers法制备氧化石墨烯(GO), 以异丙醇钛为钛源经一步水热法制备得到金红石相TiO₂-石墨烯复合材料(rGO-TiO₂), 考察了氧化石墨烯用量对复合材料光催化性能的影响. 采用X射线衍射(XRD), 比表面积(BET), 透射电镜(TEM), 扫描电镜(SEM), 拉曼光谱, 紫外-可见(UV-Vis)吸收光谱和荧光光谱(PL)等测试手段对复合材料进行表征. 结果表明: 复合材料中TiO₂为针簇状结构的金红石相, 与石墨烯能够均匀复合; 与纯金红石相TiO₂相比, 复合材料具有较大的比表面积. 研究了该复合材料在紫外光下对罗丹明B 以及可见光下对甲基橙光降解效果. 当氧化石墨烯浓度为0.5 mg·mL^-1时, 制备得到的复合材料rGO-TiO₂具有较好的光催化效果.

Preparation and Photocatalytic Activity of Rutile TiO2-Graphene Composites

In this work, graphene oxide (GO) was prepared from natural flake graphite by the modified Hummers method. A series of composites consisting of rutile TiO₂ and graphene (rGO-TiO₂) were synthesized via a one-step hydrothermal reaction of graphene oxide and titanium isopropylate. The influence of the amount of graphene oxide on the photocatalytic activity of the rGO-TiO₂ composites was studied. The photocatalysts were characterized by Brunauer-Emmett-Teller sorption (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, UV-Vis absorbance spectroscopy, and photoluminescence (PL) spectroscopy. The as-formed TiO₂ was formed in the rutile phase with a needle-cluster structure, and dispersed uniformly on the surface of graphene sheets. The composites possess higher specific areas than pure rutile TiO₂. The photo-degradation performance of Rhodamine B and methyl orange by the rGO-TiO₂ composites under ultraviolet and visible light was studied. The results indicated that rGO-TiO₂ composites prepared with 0.5 mg·mL^-1 of graphene oxide had the greatest photocatalytic activity.