Silicon-doped Boron Nitride Nanosheets for Enhanced Toxic Gas Sensing: An ab initio Approach

In this study, the performance of silicon-doped boron nitride nanosheets (Si/BNNs) was compared with pristine BNNs to sense commonly occurring toxic gases (CO, CO2, HCN, N2O, NO, NO2, O-3, and SO2). To study the sensing performance of Si/BNNs and pure BNNs, ab initio calculations based on the Kohn-Sham density functional theory (DFT) were employed. The changes in the electronic properties such as molecular potentials, distributions of the participating molecular orbitals and electronic density of states (DOS) were examined along with the evaluation of the reactivity descriptors. To probe the charge transfer during the gas sensing, atomic charges were computed. The energy accompanied by the sensing gas molecules over the nanosheet was computed to understand the thermodynamics of the sensing process. The ab initio calculations showed that Si doping significantly enhanced the sensing behaviour of BNNs by virtue of the excess free electron density present on the Si atom. The analysis also showed that the sensing strength of Si/BNNs followed the order O-3 > NO > SO2 > CO > NO2 > N2O > HCN > CO2. The computational insights can be used to design highly efficient sensors for toxic gases in terms of sensing activity and selectivity and stability of the sensing material.

Automated summary

In this study, the performance of silicon-doped boron nitride nanosheets (Si/BNNs) was compared with pristine BNNs for sensing commonly occurring toxic gases. Ab initio calculations based on density functional theory (DFT) were employed to study the sensing performance and analyze the changes in electronic properties, charge transfer, and thermodynamics of the sensing process. The results showed that Si doping significantly enhanced the sensing behavior of BNNs, and the sensing strength of Si/BNNs followed a specific order. The computational insights can be used to design efficient sensors for toxic gases in terms of sensing activity, selectivity, and stability of the sensing material.