论文部分内容阅读
为拓展二氧化钛(TiO_2)在可见光区的光响应范围,在140℃水热条件下制备了不同氧化石墨烯含量的石墨烯/二氧化钛(RGO/TiO_2)复合材料。利用X-射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)等对材料进行了表征。以甲基橙为目标污染物,研究了在模拟太阳光和紫外光照下TiO_2和RGO/TiO_2对甲基橙的光催化降解性能。结果表明,TiO_2和GO复合后,TiO_2由原来单一的金红石型转变为金红石型和锐钛矿型并存,出现了混晶效应;在模拟太阳光的条件下,复合材料的催化活性均高于TiO_2本身;光照4 h后80 mg氧化石墨烯添加量制备的复合材料对甲基橙的光催化降解率达到69.58%,是TiO_2的1.65倍;在紫外光照1.5 h时,复合材料对甲基橙的降解率达到了70%。由此可知,石墨烯的存在能够促进TiO_2半导体中电子和空穴的有效分离,显著提高了TiO_2光催化剂对可见光的响应。
In order to expand the photoreaction range of TiO2 in the visible region, graphene / TiO2 (RGO / TiO2) composites with different graphene oxide contents were prepared at 140 ℃ under hydrothermal conditions. The materials were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and the like. Using methyl orange as the target pollutant, the photocatalytic degradation of methyl orange by TiO 2 and RGO / TiO 2 under simulated sunlight and ultraviolet irradiation was studied. The results showed that the photocatalytic activity of the composites changed from single rutile to rutile and anatase, and the photocatalytic activity of the composites was higher than that of TiO_2 The photocatalytic degradation rate of methyl orange prepared by adding 80 mg of graphene oxide after exposure to light for 4 h reached 69.58%, which was 1.65 times of that of TiO 2. Under UV light irradiation for 1.5 h, the photocatalytic degradation rate of methyl orange to methyl orange Degradation rate reached 70%. It can be seen that the presence of graphene can promote the effective separation of electrons and holes in the TiO 2 semiconductor and significantly improve the response of the TiO 2 photocatalyst to visible light.