CuS-Doped Ti3C2 MXene Nanosheets for Highly Efficient Adsorption of Elemental Mercury in Flue Gas

Mercury pollution in flue gas from coal-fired power plants will seriously harm the ecological environment and biological safety. The flue gas is often accompanied by acid gases (SO2, NO), which will seriously affect the efficiency of the mercury adsorbent. In this work, a new type of metal sulfide CuS-modified Ti3C2 adsorbent has been prepared, which has a strong resistance to acid gases. Moreover, when the weight percentage of CuS is 10 wt %, the synthesized composite material (TC-10) has a very excellent efficiency of mercury removal, and the adsorption capacity is as high as 20.478 mg·g–1. X-ray photoelectron spectroscopy results show that disulfide ions (S22−) and adsorbed oxygen are the main active substances. 3DFT calculation was used to further analyze the interaction between Hg0 and the pristine Ti3C2 adsorbent and the modified CuS/Ti3C2. Results show that CuS doping increases the activity of the pristine Ti3C2 surface. Therefore, this study proves that CuS/Ti3C2 is a promising material for removing mercury from coal-fired power plants and expands the application range of MXene.