▎ 摘　　要

Elemental mercury (Hg-0) is a widespread concern due to its high toxic and long residence time in the environment. Ag/graphene composite was synthesized as a high efficient and recyclable sorbent for Hg-0 removal. Ag particles were doped on the surface of graphene by a facile in situ chemical synthesis method. FTIR, XRD, and TEM results showed that Ag nanoparticles successfully grew on the surface of graphene layers. The performance of Ag/graphene as a sorbent was tested under a fix-bed reactor and the results showed that it could completely capture Hg-0 at ambient temperature (25 degrees C). The Hg-0 capacity was as high as 4.2 mg/g. The Hg-0 removal efficiency decreased from 94% to 60% when the temperature increased from 25 to 100 degrees C, respectively. SO2 and NO had nearly no effect on Hg-0 removal, but the efficiency dropped by about 4% when O-2 existed. Hg-TPD results showed that mercury can be rapidly and efficiently released from the composite by thermal separation. The adsorption capacity of Hg-0 had no degradation after six cycles. The high Hg-0 capacity and recyclability make the Ag/graphene a candidate for the removal at ambient temperature. (C) 2015 Elsevier B.V. All rights reserved.