ZnO/RGO复合材料的结构及其光催化性能研究

Structure and Photocatalytic Properties of ZnO/RGO Composite

本实验以ZnSO4和氧化石墨(Graphite Oxide,GO)原料,在低温环境下(60℃)制备了层状ZnO/RGO(ZnO/Reduced GraphiteOxide)复合材料。通过对ZnO/RGO复合材料进行XRD、FTIR、XPS和FE-SEM等测试,表征了产物的晶相结构、界面状况及微观形貌特征。氧化石墨在与ZnO的复合反应过程中其活性基团消失或减弱,氧化石墨自身被还原为一种类石墨物质(ReducedGO,RGO);GO的预处理过程对产物的形貌有较大影响,采用稀碱溶液对石墨的剥离处理有利于产物的层状结构形成。本文还以甲基橙为目标降解物,考察了不同条件下所得催化剂的紫外光催化性能。研究表明,ZnO/RGO纳米复合材料大大提高了ZnO紫外光催化活性。光致发光谱(PL)显示,ZnO/RGO复合材料的荧光发射峰强度比纯ZnO有较大降低,说明ZnO的光激发电子在氧化石墨的还原产物RGO和ZnO纳米颗粒之间存在界面电子转移效应,因而抑制了ZnO中光生电子-空穴对的复合,从而提高了ZnO的光催化性能。

ZnO/RGO （ZnO/Reduced Graphite Oxide） composites were synthesized at low temperature （60 ℃） using ZnSO4 and GO （Graphite Oxide） as precursors. The as-prepared samples have been characterized by X-ray diffraction （XRD）, FTIR, X-ray Photoelectron Spectroscopy （XPS）, Field Emission Scanning Electron Microscopy （FE-SEM）, etc. During the formation the composites, GO was reduced to RGO （Reduced Graphite Oxide, RGO）. The actives groups, such as C =O and C-O-C disappeared or sharply weakened, while C =C appeared in the reaction processes. The ZnO/RGO composites have layered structures, which greatly dependent on the pretreatment means of GO. Compared with pure ZnO, ZnO/RGO composites showed greatly enhanced UV photocatalytic activity. Photoluminescence （PL） spectra of ZnO/RGO showed a significant decline compared to that of pure ZnO, suggesting the inhibited recombination of excited electron hole pair （e^--h^＋）. The enhancement of photocatalytic activity for ZnO/RGO could be attributed the migration effect of photoinduced electrons on the interface of RGO and ZnO.