Spherical-shaped CuS modified carbon nitride nanosheet for efficient capture of elemental mercury from flue gas at low temperature

Mercury (Hg0) pollution poses a huge threat to human health and the environment due to its high toxicity, long persistence and bioaccumulation in the environment. Most of the traditional Hg0 adsorbents have a low reaction rate, high operating cost, especially poor resistance to SO2, which limited their practical application. In this work, nanosheet g-C3N4 was used as the support and modified by CuS to capture flue gas mercury. Take advantage of the large specific surface area of g-C3N4 to increase the BET of the composite and decrease the use of CuS. The effects of CuS loading, reaction temperature, and common components in the coal-fired flue gas on the mercury removal performance were studied respectively. The experimental outcomes showed that the 10CuS/g-C3N4 (10CuS/CN) reaches as high as almost 100% Hg0 removal efficiency under the temperature of 40–120 ℃. Meanwhile the common components like SO2, NO, HCl and H2O have no obvious inhibition effects on Hg0 removal efficiency of the 10CuS/CN adsorbent. Sx2- and Cu2+ as the primary bonding sites shows a synergy effect on Hg0 removal. 10CuS/CN is a promising material for Hg0 removal under various flue gas conditions, which is expected to be a substitute for traditional adsorbents.