中文摘要：

采用水热法制备了一系列混合相二氧化钛-石墨烯（Tr G）的复合物,并考察了石墨烯的用量对降解污染物甲基蓝的影响.采用X射线衍射（XRD）,傅里叶变换红外（FTIR）光谱,高分辨透射电镜（HRTEM）,拉曼光谱,紫外-可见漫反射吸收光谱（UV-Vis DRS）,X射线光电子能谱（XPS）和比表面积（BET）等测试手段对复合材料进行表征.结果表明,复合材料中Ti O2为棒状的混合相,且均匀分散在石墨烯表面.由于石墨烯良好的吸光性能,混合相中的异质结和复合物的良好光电子传递能力以及高比表面积,复合材料具有较高的光催化活性.所制备的Tr G复合材料在紫外光下降解甲基蓝的催化活性均高于纯Ti O2,且当氧化石墨烯负载量为0.8%（质量分数,w）时,复合材料Tr G具有较好的光催化效果.

英文摘要：

A series of composites consisting of anatase-rutile Ti O2 and graphene（Tr G） were synthesized by a hydrothermal route. The influence of the amount of graphene oxide on the photocatalytic activity during the degradation of methyl blue was studied. The photocatalysts were characterized by X-ray diffraction（XRD）,Fourier transform infrared（FTIR） spectroscopy, high-resolution transmission electron microscopy（HRTEM）,Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy（UV-Vis DRS）, X-ray photoelectron spectroscopy（XPS）, and Brunauer-Emmett-Teller（BET） specific surface area measurements. The results show that as-prepared Ti O2 formed in the anatase and rutile phase with a bar structure and it dispersed uniformly over the surface of the graphene sheets. The composites possess higher catalytic activity because of the strong absorption capacity of graphene, the establishment of heterojunctions between rutile and anatase Ti O2, the remarkable electrical transport between Ti O2 and graphene and the high specific surface areas. The photodegradation performance of methyl blue by the Tr G composites under UV light was studied. Our results indicate that the photocatalytic activities of titanium dioxide-graphene composites were higher than those of pure Ti O2. We also found that the Tr G composites prepared with a loading of 0.8%（mass fraction, w） graphene oxide had the best photocatalytic activity.