▎ 摘　　要

Herein, we report a novel in situ CeO2 grafted graphene synthesized by simple one step hydrothermal reactions, where concentration of ceria is varied instead of graphene. The ammonia-assisted single step hydrothermal method is a beneficial route to prepare CeO2/RGO nanocomposites without employing any toxic reducing reagent. The enhancement in the photoactivity of optimized catalyst is attributable to high adsorptivity of dye, extended photosorption and enhanced charge separation and transportation characteristics. It is found that the concentration of CeO2 to RGO in the composite controls the photoactivity. The results showed that the composite with 2:1 ratio of CeO2 to RGO exhibited relatively higher photoactivity compared to the bare CeO2 catalyst. The study is supported by using XRD, FE-SEM, EDS, HR-TEM, Raman, UV-vis, FTIR, and XPS analysis techniques. Thus, the results provide quantitative evidence for the critical role of graphene-CeO2 interface in charge separation as well CeO2 content of the material. The present finding may open a new avenue in the investigation of CeO2/RGO nanocomposites with optimized CeO2 content for addressing various environmental issues.