The heterogeneous photocatalytic process has been considered as one of the most emerging methods for treatment of dye wastewater due to its cost-effectiveness, efficiency and stability. This study focuses on achieving excellent photocatalytic performance by dispersing Zinc oxide within the rGO sheets. In a two-step method, Zinc oxide-reduced graphene oxide (ZnO-rGO) composites were synthesized, initially KOH reacts with Zinc acetate in the aqueous dispersions of graphene oxide (GO) to form a Zn(OH)₂/graphene oxide precursor, followed by thermal treatment follows.
It is found that the dispersion of Zinc oxide within the rGO sheets is a key for achieving an excellent catalytic performance of the samples. ZnO-rGO composite with suitable mass ratio achieved more photocatalytic activity than pure ZnO. ZnO s ability to accept electrons is promoted by the rGO support. As a result, enhancement in photocatalytic activity is obtained. The samples are characterized by XRD, SEM, EDAX and UV–VIS diffuse reflectance spectroscopy methods. The photocatalytic activity of ZnO-rGO has been examined by degradation of the Direct blue 199 dye wastewater. 99.6% of dye degradation was obtained using ZnO-rGO composites.

中文翻译：

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ZnO-rGO纳米复合材料作为染料降解中的高性能光催化剂

由于其成本效益，效率和稳定性，非均相光催化工艺已被视为处理染料废水的最新方法之一。这项研究致力于通过将氧化锌分散在rGO片材中来实现出色的光催化性能。在两步法中，合成了氧化锌还原的氧化石墨烯（ZnO-rGO）复合材料，最初，KOH与乙酸锌在氧化石墨烯（GO）的水分散体中反应，形成Zn（OH）₂ /氧化石墨烯前体，然后进行热处理。
已经发现，氧化锌在rGO片材中的分散是实现样品出色的催化性能的关键。质量比合适的ZnO-rGO复合材料比纯ZnO具有更高的光催化活性。rGO的支持促进了ZnO接受电子的能力。结果，获得了光催化活性的增强。样品通过XRD，SEM，EDAX和UV-VIS漫反射光谱法进行表征。ZnO-rGO的光催化活性已通过降解直接蓝199染料废水进行了研究。使用ZnO-rGO复合材料可获得99.6％的染料降解。