▎ 摘　　要

Here we report that poly(diallyldimethylammonium chloride) (PDDA) acts as both a reducing agent and a stabilizer to prepare soluble graphene nanosheets from graphite oxide. The results of transmission electron microscopy, X-ray, diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and Fourier transform infrared indicated that graphite oxide was successfully reduced to graphene nanosheets which exhibited single layer structure and high dispersion In various solvents. The reaction mechanism for PDDA-induced reduction of exfoliated graphite oxide was proposed. Furthermore, PDDA facilitated the In situ growth of highly dispersed Pt nanoparticles on the surface of graphene nanosheets to form Pt/graphene nanocomposites; which exhibited excellent catalytic activity toward formic acid oxidation., This work presents a facile and environmentally friendly approach to the synthesis of graphene nanosheets and opens up a new possibility for preparing graphene and graphene-based nanomaterials for large-scale applications.