石墨烯/TiO_2复合物的制备及其光催化性能

Preparation and photocatalytic performance of RGO/TiO_2 nano-composite material

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。

Hydro-thermal method was adopted to prepare RGO / TiO2 composite photocatalyst materials with various addition of graphite oxide under 140℃ in order to expand titanium dioxide＇s response to visible light. The materials were characterized by X ray diffractometry,scanning electron microscope etc. The activities of these photocatalysts were evaluated by photodegradation of methyl-orange irradiated under simulated sunlight and UV light.The results indicated that TiO2＇s single anatase phase turned into anatase-rutile mixed phase after TiO2 and GO complex. The photocatalytic activitives of nanocomposites were better than those of TiO2 nanoparticles with simulated sunlight irradiating. The photocatalytic degradation efficiency of the the nanocomposites degradation rate reached 69. 58%,1. 65 times as much as pure TiO2. Photodegradation rates of RGO / TiO2 composites for methyl orange under UV light irradiation reached 70% when radiated 1. 5 hours. It could be seen that the exist of reduced graphene oxide nanosheets can improve the efficiency of TiO2 response to visible light by promoting the effective separation of electron-hole pair in TiO2,and it significantly improved the TiO2 photocatalyst respond to visible light.