Silicene as an efficient way to fully inactivate the SO2 pollutant

Abstract

Sulfur dioxide (SO2) is a major air pollutant, responsible for the acid rain. As consequence, it has significant negative impacts on human health, and on the environment. Therefore, removing it from the air is a necessity. We propose the use of silicene (a single layer of Si atoms), not only to detect SO2 molecules, but also to fully inactivate them. The process starts by chemically adsorbing the molecule on the silicene sheets. Afterward, one of the O atoms breaks away from the molecule, and it directly attaches to the surface. The energy barrier to carry out this process is ~ 0.65 eV, lower than the energy needed to desorb the molecule from the surface. The reaction further proceeds by breaking the remaining SO unit, with an energy barrier of ~0.54 eV. In the final state, the oxygen atoms form silicene oxide lines, which are separated by sulfur atoms attached to the substrate. This system paves the way to use silicene as a new and potentially efficient device to eliminate the air polluting SO2 molecules.