Toxic gas molecules adsorbed on the original and metal-doped two-dimensional s-C3N4: A first-principles investigation

We theoretically investigate toxic gas molecules including CO, NO, NO₂, SO₂, and H₂S adsorbed on the original s-C₃N₄ and Cu, V and Fe-doped s-C₃N₄. V- and Cu-doped s-C₃N₄ structures have the semiconductor-to-conductor transitions. All the gas molecules prefer to be adsorbed on the metal-doped s-C₃N₄ than the pristine one. In addition, it also reveals that both original and metal-doped s-C₃N₄ materials provide better adsorption performance than most reported C_xN_y ones. The ab initio molecular dynamics simulations illustrate that Cu-doped s-C₃N₄ obtain the capacity for the decomposition of H₂S at 500 K. Similar decomposition of NO₂, SO₂ and H₂S by Cu-doped s-C₃N₄, and NO₂ and H₂S by Fe-doped s-C₃N₄ could also be observed. The other molecules could desorb from metal-doped s-C₃N₄. In addition, the metal atoms selected for the metal-doped s-C₃N₄ are economically advantageous. Thus, the cheap-metal-doped s-C₃N₄ shows good gas adsorption and decomposition capacity, and these studies may provide insights for the applications of metal-doped s-C₃N₄.