金红石相TiO2-石墨烯复合材料的制备及其光催化性能

摘要

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.%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-Tel er 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.