Metal-modified C3N1 monolayer sensors for battery instability monitoring†
Abstract
The pressing need for affordable gas sensors with enhanced sensitivity and selectivity in identifying hazardous gases released after the battery becomes unstable cannot be overstated. In this study, a C3N1 monolayer modified with Cu and Ag atoms (Cu/Ag–C2N1) was selected to achieve selective adsorption of NO2 under the coexistence of multiple gases (PF5, NH3, H2O, C2H4, and C2H6) based on density functional theory. The results demonstrate that securely anchoring metal atoms to the monolayer, as indicated by cohesion energy and ab initio molecular dynamics simulations, concurrently enhances the material's conductivity. Analyses of electrostatic potential and work function identified high activity sites and electron-releasing capabilities. Furthermore, the gas–solid interface structures of multiple gases on the Cu/Ag–C2N1 monolayers are revealed by the adsorption energy and distance. Importantly, NO2 exhibits stronger adsorption energy on Cu/Ag–C2N1, reaching −3.54 and −3.27 eV, respectively. Crystal Orbital Hamilton Population and d-band center theory unveiled differences in adsorption energy resulting from the modification involving the two metals. Fascinatingly, density of states calculation demonstrates, for the first time, that the two doped metal monolayers generate a distinct response solely to NO2 in a multi-gas coexistence setting, effectively excluding interference from water. In practice, based on Gibbs free energy and Einstein diffusion law calculations, Cu–C2N1 exhibits superior hydrophobicity, a broader temperature range and a lower diffusion activation energy barrier (2.5 kJ mol−1). Our theoretical calculations demonstrate Cu's efficacy in substituting expensive Ag, yielding cost-effectiveness without compromising selectivity, response, stability, and versatility.
- This article is part of the themed collection: Today's Simulations: Pioneering the Experiments of Tomorrow