Enhancement of gas sensing by doping of transition metal in two-dimensional As2C3 nanosheet: A density functional theory investigation

Abstract

We have been motivated to explore the quest for an appropriate 2D material with the potential to capture toxic nitrogen-containing gasses (NH3, NO2, and NO). We have calculated the structural, electronic, and adsorption properties of 2D As2C3 nanosheets. The density functional theory (DFT) calculations show that NO2 and NH3 are weakly binding with the pristine As2C3 nanosheet, which restricts the use of the latter as effective sensing materials. At the same time, the NO molecule reveals better adsorption property and a significant amount of charge transfer of 0.30 e. However, the adsorption energies are significantly enhanced by introducing the doping of transition metal elements (Cu, Pd, and Pt) into the As2C3 nanosheet. Our dispersion-corrected DFT-D3 calculations found that Cu, Pd, and Pt dopants in As2C3 nanosheet not only improve the adsorption property but also significantly moderate the electronic properties, charge transfer, and work function, etc. A Bader charge transfer mechanism suggests that the amount of charge transfer from nanosheet to the NCGs and vice-versa is responsible for enhancing the sensing characteristics. Our theoretical results reveal that 0.90% doping of TM elements in As2C3 nanosheet makes it a suitable and efficient sensing device to detect the toxic pollutant gases.