Chemical functionalization of BN graphene with the metal-arene group: a theoretical study

Abstract

Chemical functionalization of BN graphene allows wider flexibility in engineering its electronic and magnetic properties as well as its chemical reactivity, thus making it have potential applications in many fields. In the present work, the chemical functionalization of BN graphene with six different metal-arenes (MC₆H₆, M = Ti, V, Cr, Mn, Fe, and Co) has been studied systematically by performing density functional theory (DFT) calculations. Particular attention is paid to searching for the most stable configurations, calculating the corresponding binding energies, and evaluating the effects of MC₆H₆ functionalization on the electronic and magnetic properties of BN graphene. We find that all of the studied MC₆H₆ groups can be stably adsorbed on BN graphene, with binding energies ranging from 0.97 eV (for FeC₆H₆) to 1.40 eV (for MnC₆H₆), which are weakly dependent on the concentration of adsorbates. Moreover, the adsorption of MC₆H₆ groups can induce certain impurity states within the band gap of the pristine BN graphene, leading to a reduction of the band gap. Most MC₆H₆/BN graphenes exhibit nonzero magnetic moments, contributed largely by the transition metal atoms. Interestingly, the adsorption of an O₂ molecule on BN graphene is greatly enhanced due to MC₆H₆ functionalization. The elongation of the O–O bonds of the adsorbed O₂ molecules indicates that MC₆H₆/BN graphenes could be used to fabricate oxidative catalysts.