Both zinc oxide (ZnO) and reduced graphene oxide (rGO) are known for its attractive optical properties in their nano form. Here, ZnO-rGO nanocomposites and rGO were prepared via simple and reproducible hydrothermal as well as modified Hummer’s method. Microstructural identification of phase formation and dispersion of ZnO on rGO was confirmed by X-ray diffraction and transmission electron microscopy (TEM) measurements. The reduction of graphene oxide was confirmed by the appearance of D and G band peaks in Raman spectra. Optical bandgap of samples was estimated by UV–Visible diffused reflectance spectroscopy up to IR region. A systematic study of photocatalytic behavior towards the degradation of organic dyes such as methyl orange and rhodamine B under the influence of UV light source is demonstrated. Better than 85% of degradation was measured for both the dyes in the presence of ZnO-rGO composite during 2 h of UV illuminations. The enhanced photocatalytic activity of the composites is attributed to electron–hole charge transfer, which also promises its use in photovoltaics.

中文翻译：

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ZnO-rGO纳米复合材料的物理性质和增强的光催化活性

氧化锌 (ZnO) 和还原氧化石墨烯 (rGO) 都以其纳米形式的有吸引力的光学特性而闻名。在这里，ZnO-rGO 纳米复合材料和 rGO 是通过简单且可重复的水热法以及改进的 Hummer 方法制备的。X 射线衍射和透射电子显微镜 (TEM) 测量证实了 ZnO 在 rGO 上的相形成和分散的微观结构鉴定。通过拉曼光谱中 D 和 G 带峰的出现证实了氧化石墨烯的还原。样品的光学带隙通过紫外-可见漫反射光谱法估计到红外区域。展示了在紫外光源影响下降解有机染料如甲基橙和罗丹明 B 的光催化行为的系统研究。在 ZnO-rGO 复合材料的存在下，在 2 小时的紫外线照射期间，两种染料的降解率均优于 85%。复合材料增强的光催化活性归因于电子-空穴电荷转移，这也有望用于光伏。