▎ 摘　　要

In situ growth of naked Ag nanoparticles on graphene oxide was achieved following a simple, green, and environment-friendly one-step stirring method. In the absence of extra reductant and stabilizer, the naked Ag nanoparticles formed on the surface of GO via a spontaneous redox reaction between Ag(+)and GO at room temperature. The morphology and microstructure of the resultant heterogeneous nanostructures were characterized by various spectroscopic and microscopic techniques systematically. The characterization results showed that the naked metallic Ag nanoparticles with an average diameter of 4.31 +/- 0.13 nm distribute homogeneously and tend to "stand" in line on GO. The well-known catalytic hydrogenation of 4-nitrophenol by NaBH(4)was carried out to investigate the potential catalytic activity of the obtained heterogeneous Ag/GO nanocomposite. The obtained Ag/GO nanocomposite exhibited high catalytic ability with the apparent kinetics constant of 1.856 min(-1)and high turnover frequency of 2131.6 h(-1)and high structural and performance stability. It is believed that the small size and naked surface of the Ag nanoparticles, which provide abundant exposed catalytically active sites, facilitate greatly in improving the catalytic performance of Ag/GO. It is anticipated that the proposed green method is extendible to prepare other efficient noble-metal/GO nanocatalyst.