First principles investigations of Cobalt and Manganese doped boron nitride nanosheet for gas sensing application

In the present study, Cobalt (Co) and Manganese (Mn) doped Boron Nitride nanosheet (BNNS) has been designed for density functional theory calculation. The variation in structural, electronic, and optical properties of BNNS due to Co and Mn doping has been studied along with the gas sensing ability of the designed nanosheets towards CH4, H2S, NH3, O3, PH3, and SO2 hazardous gases. Co and Mn doping in the BNNS result in an insulator-to-conductor and insulator-to-semiconductor transition, respectively. Co and Mn-doped BNNS show a stronger interaction with the selected gases resulting in high adsorption energy. The designed sheets show the strongest interaction with the O3 molecule resulting in a very high recovery time. Though doping results in significant structural deformation of the BNNS, a slight variation in bond length is observed due to gas adsorption. BNNS demonstrate a substantial drop in the band gap due to O3 and SO2 adsorption. In other cases, significant variations in the band gap of all the designed sheets are observed after gas adsorption. All the structures show a very high absorption coefficient of 105 cm−1 order which shows a slight peak shifting due to the interaction with toxic gases.