Abstract: Firstly, graphene oxide (GO) was prepared by modified Hummers method. Secondly, Ag/GO colloids were 
synthesized from GO and using glucose as reducing agent to reduce silver nanoparticles in silver ammonia solution. Finally, Ag/GO coating was obtained under vacuum drying condition, and Ag/reduced graphene oxide (rGO) coating was prepared
 by vacuum stepby\|step thermal reduction technology. The structure and morphology of the films were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The hydrophilic/hydrophobic and antibacterial properties of the samples were tested by wetting angle tester and inhibition zone method. The results show that the graphenebased coatings have a good combination with the substrate, Ag nanoparticles are spherical shape and uniformly distributed between the layers of graphene sheets, and the particle size range is 20—50 nm. No bacterial was observed on the surface of GO and rGO films, and no clear zone of inhibition is found in E.coli and S.aureus. Compared with the Ag/GO composite film, Ag/rGO composite film has stronger antibacterial activity, and low temperature 
annealing is helpful to improve the antibacterial performance of graphenebased composite coating.

Key words: graphenebased coating material, Ag/graphene antibacterial coating, stepbystep thermal reduction