Computer-aided study on the two-dimensional hexagonal boron phosphide nanosheets for selective detection of ambient toxic gas

As industrialization progresses, numerous harmful gases are released into the atmosphere. However, detecting these gases at low concentrations poses a significant challenge. Consequently, there is an urgent need to create advanced toxic gas sensors that can effectively identify and measure these substances. The utilization of two-dimensional materials offers promising opportunities for gas sensors due to their notable benefits, including substantial distinctive electronic properties and specific surface area. In this research, a single layer of hexagonal boron phosphide (h-BP) was employed as the substrate material. Using density-functional theory (DFT) calculations, the researchers investigated how ambient toxic gases, namely CO, SO₂, HCN, and CS₂, are absorbed on the surface of monolayers of h-BP. The findings indicate that interaction between h-BP and these gases is characterized by physical adsorption. The researchers conducted calculations on four ideal adsorption structures to assess the Bader charge, density of states (DOS), work function, and recovery time. The results revealed notable alterations in electronic features and work function of the h-BP monolayer when it was exposed to SO₂, indicating substantial modifications in electrical signals while detecting gas. Findings of this investigation demonstrate that h-BP monolayer exhibits enhanced sensitivity and selectivity towards the hazardous gas SO₂.