Structural, Electronic and Thermochemical Characterizing the Graphene Doped with Transition Metals for Nitrogen Dioxide Adsorption: A Gas Sensing Study by Ab Initio Method

Abstract

In this research, nitrogen dioxide (NO2) adsorption on doped pristine graphene (Gr) sheets with transition metals (TM) of manganese (Mn), cobalt (Co), and copper ( Cu) has been applied for scavenging this toxic gas as the environmental pollutant. TM@GR yields higher activity toward gas sensing than pure graphene. The thermodynamic results from IR spectroscopy have indicated that 〖∆G〗_(ads,NO2→TM@C-NG)^o values are similar for different metal transitions of Mn, Co, Cu, which exhibit the accord of the estimated data by all approaches. Our results have provided a favorable understanding of the interaction between TM-doped graphene nanosheet and NO2 gas molecule. The bonding of NO2 molecule to transition metals of Mn, Co, and Cu can be observed as beginning by transferring the unpaired electron into empty d orbitals of transition metal atoms. Moreover, NQR method with EPR-III basis set for N-atoms has approved the efficiency of nitrogen dioxide as the detectors for promising scavengers through the graph analysis of :O ̈:-N ̇=O ̈: → Mn@ C-Gr, :O ̈:-N ̇=O ̈: →Co @C-Gr, :O ̈:-N ̇=O ̈: → Cu @C-Gr complexes. Furthermore, the results of partial electron density states (PDOS) have confirmed an obvious charge accumulation between the graphene and doped atoms Mn, Co, Cu through NO2 adsorption. Frontier molecular orbital’s of HOMO, LUMO, and band energy gap accompanying some chemical reactivity parameters have represented the attributes of molecular electrical transport of (Mn, Co, Cu) doping of carbon nanographene for NO2 adsorption.