Graphene-like BC6N nanosheets are potential candidates for detection of volatile organic compounds (VOCs) in human breath: A DFT study

In this work, we employ first-principles density functional theory calculations and nonequilibrium Green's function formalism to investigate the potential application of graphene-like borocarbonitride BC6N) for high-performance volatile organic compound (VOC) sensors used for human breath analysis. The adsorption behaviors of several VOCs (acetone, ethanol, methanol, formaldehyde, and toluene) and interfering gases in exhaled breath (carbon dioxide and water) are examined. The BC6N monolayer is a semiconductor with a bandgap of 1.228 eV. It is discovered that all the above gas molecules are physisorbed on the pristine BC6N sheet. The energy bandgap of pristine BC6N is slightly altered after interaction with the gas molecules. It is revealed that introducing a single carbon vacancy in the BC6N sheet can significantly increase the adsorption energies of the gas molecules. The modification of current-voltage responses due to VOC's disclose that the sensor shows high sensitivity, selectivity and short recovery for ethanol. Our results suggest that defective BC6N is a compelling and feasible candidate for chemiresistive sensors for applications in room temperature breath analysis of VOCs.