Tuning the electronic, magnetic, and sensing properties of a single atom embedded microporous C3N6 monolayer towards XO2 (X = C, N, S) gases

Abstract

Two-dimensional frameworks have attracted significant attention due to their great potential in many applications. Among the g-CxNy family, C3N6 is one of the recently synthesized promising candidates, which exhibits semiconducting behavior. Motivated by its potential, we performed first-principles density functional theory (DFT) calculations to explore the structural, electronic, magnetic, and gas sensing properties of the C3N6 ML towards common pollutants, such as XO2 (X = C, N, and S). We found weak binding between the pristine C3N6 ML and XO2, which was not suitable for efficient gas capture. However, functionalization with a selected transition metal not only altered the electronic and magnetic properties but also improved the sensing behavior of TM-C3N6 (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn). We have analyzed the adsorption behavior, desorption time, and correlation matrix of TM embedded C3N6 towards XO2 (X = C, N, and S) gases. Electronic structures and magnetic moments of XO2 adsorbed TM-C3N6 depend on the atomic number of the embedded TM atom and the adsorbed gas molecules. We found that the adsorption energies of TM-C3N6 systems towards NO2 gas molecules are stronger in comparison to CO2 and SO2 gas molecules, which suggested a selective capture mechanism. Based on our findings, TM-C3N6 systems turned out to be promising adsorbent materials for environmentally toxic pollutants.