The potential of 2D carbon nitride monolayer as an efficient adsorbent for capturing mercury: A DFT study

Abstract

Owing to its large surface area and the close similarity between nitrogen and mercury (Hg) in C3N, two-dimensional C3N monolayer has the potential of controlling the release of gaseous Hg0. Using density functional theory (DFT), we investigated the adsorption and conversion mechanism of Hg species on this monolayer surface. The findings demonstrated that C4N2 site on the surface of the C3N monolayer is more capable of adsorbing Hg0 than C6 site. Also, the recovery time of the C3N monolayer for Hg0 was approximately 17.63 s and 3.49 μs at 298 and 400 K, respectively. The analyses of electronic structure, charge transport, geometric structure, and adsorption stability demonstrated that the C3N monolayer is an encouraging material for Hg0 adsorption. The C3N monolayer could adsorb the oxidizing species of mercury (namely HgBr, HgCl, HgS, and HgO,) more easily than Hg0, with higher adsorption energy. Overall, the C3N monolayer is a promising sorbent material, which is capable of controlling gaseous mercury in an efficient way.