LAUSR

Carbon nitride nanosheet (CNNS) is facilely synthesized via a two-step thermal oxidative etching approach and then decorated with MnO2 nanoparticles via incipient wetness impregnation method for Hg0 removal at low temperature. Pristine CNNS exhibits a good Hg0 adsorption performance associated with the optimal Hg0 removal efficiency of ∼65.8% at 150 °C due to its two-dimensional planar structure and big surface area. MnO2 decoration can greatly enhance the Hg0 removal performance of CNNS, presumably ascribed to the improved electron transfer at the interface of MnO2 and g-C3N4. 10MnO2/CNNS presents a superior Hg0 oxidation ability with Hg0 removal efficiencies all above 91% within the temperature range of 90–240 °C. The long-term test and XPS analysis disclose that 10MnO2/CNNS is a cost-effective catalyst/sorbent for oxidation removal of elemental mercury. The gaseous Hg0 is oxidized into HgO by the lattice oxygen of MnO2, which is the dominant active site for Hg0 oxidation via redox couple of Mn4+/Mn3+.