▎ 摘　　要

Copper nanoparticles fabricated onto reduced graphene oxide (Cu NPs/rGO) were successfully synthesized via a one-pot dimethylformamide (DMF) reduction approach with an addition of nominal water. This small amount of water can significantly decrease the degree of GO reduction by DMF. As a result, the remaining oxygen-containing functionality on rGO can still interact with the copper cation precursor leading to the high Cu content fabricated onto the support material, which was evidenced by X-ray photoelectron spectroscopy (XPS). Moreover, small particle sizes and high dispersion of Cu NPs on rGO were confirmed by scanning transmission electron microscopy (STEM). In addition, our Cu NPs/rGO was competent to catalyze the Ullmann-coupling reaction (i.e., arylation of 3,5-dimethylphenol with 86% yield and turnover number 2,642).