Adsorption Mechanism and Optical Behaviors of Typical Volatile Organic Compounds on Pristine and Cu/Ni‐Modified C3N Monolayer: A First‐Principles Study.

In this paper, the geometric and electronic structure of four gas molecules, including CH4, CH2O, CH3Cl and C6H6, on pristine and Cu/Ni‐modified C3N monolayer are investigated by using First principles. The calculations show that the Cu/Ni‐doping can effectively strengthen the gas adsorption ability of C3N. Upon gas‐C3N configuration, the adsorption energies are CH2O (0.11 eV) > C6H6 (0.09 eV) > CH3Cl (0.08 eV) > CH4 (0.05 eV). For Cu‐C3N configuration, the adsorption energies are C6H6 (3.26 eV) > CH3Cl (3.24 eV) > CH4 (3.22 eV) > CH2O (3.13 eV). For Ni‐C3N configuration, the adsorption energies are CH2O (1.48 eV) > C6H6 (0.66 eV) > CH3Cl (0.39 eV) > CH4 (0.11 eV). It is worth mentioning that the magnetic moment is reduced to 0 µB when CH2O are adsorbed on Cu/Ni‐C3N, and the maximum charge transfer is 0.71 e, 0.62 e, respectively. Moreover, its optical properties of adsorption of Volatile organic compounds (VOCs) gas molecules are studied. It can be found that the two main absorption peaks locate at 3.0 × 105 cm−1 nm and 2.8 × 105 cm−1 nm at the range of ultraviolet and visible light. The calculated results provide the theoretical reference for Cu‐C3N‐based VOCs sensors. [ABSTRACT FROM AUTHOR]