Tuning and monitoring of nitrogen dioxide fixation on Cu decorated graphene: a density functional theory study.

The recycling utilization of harmful nitrogen dioxide (NO) is of great significance in pollutant control, agriculture and chemical industry. Herein, NOfixation using Cu decorated graphene (Cu/G) as an efficient adsorption platform is investigated through density functional theory calculations. Cu atom serves as the active site for NOadsorption due to the location of highest occupied molecular orbitals of Cu/G. Consequently, electrons are transferred from Cu atom to NO, resulting in NOchemisorption with the large exothermicity of 3.210 eV. Electronic structure analysis further reveals the strong hybridization of NOwith Cu is attributed to the formation of co-valence bond. Cu decorated site can adsorb up to 4 NOmolecules, while more NOmolecules are thermodynamically and kinetically favorable to form NO. Moreover, the fast release of NOmolecules is achieved when 2.0 hole is applied to Cu/G as evidenced by themolecular dynamic simulation. Importantly, the adsorption of NOcan be monitored real-time based on the conductivity change induced by the charge transfer and orbital hybridization. The behaviors and electronic monitoring of NOadsorption provide valuable guidance for future application of Cu/G as a potential material for NOfixation.