▎ 摘　　要

In this paper, a facile, economical and environmentally friendly synthetic method was developed to fabricate a Ag nanoparticle ( NP) decorated graphene ( GR/TA/Ag) composite with tannic acid ( TA) as a reducing agent and stabilizing agent. The GR/TA/Ag composite was fully characterized using Fourier transform infrared spectroscopy ( FTIR), ultraviolet-visible absorption spectroscopy ( UV-vis), Raman spectroscopy, and X-ray photoelectron spectroscopy ( XPS). Scanning electron microscopy ( SEM) and transmission electron microscopy ( TEM) demonstrated that Ag NPs with diameters of up to 6 nm were homogeneously and uniformly deposited on graphene sheets. With an increasing concentration of AgNO3 used for immersion, the amount of Ag NPs loaded kept increasing without aggregation or deformation. The antibacterial properties of the GR/TA/Ag composite were studied using Gram-negative E. coli ATCC 25922 and Gram-positive S. aureus ATCC 6538 via both the disk diffusion method and the shaking flask method. The disk diffusion method results showed that the synthesized GR/TA/Ag composite had great release antibacterial properties owing to the loading of Ag NPs. In addition, the presence of TA gave the composite good non-release antibacterial properties, based on the results of the shaking flask method. The ingenious combination of the release-killing capabilities of Ag NPs and the contact-killing capabilities of TA bestow two-level antibacterial activity on the GR/TA/Ag composite, promoting the GR/TA/Ag composite as part of a new generation of powerful antibacterial agents with promising applications.