Charge-controlled switchable methane adsorption on heteroatom-doped BNNSs

Abstract

The adsorption behavior of methane (CH₄) on neutral and charged states of Al-, C-, P- and Si-doped boron nitride nanosheets (BNNSs), is investigated using the density functional theory (DFT) method. The thermodynamic stability and structural parameters of all studied adsorbents in both cases of the B atom, X(B), and N atom, Y(N), replaced by a doped atom (X or Y =Al, C, P, Si) were evaluated. It is found that replacing N atom from BNNS by Al (Al(N)) can notably enhance the adsorption energy (E_ads) of CH₄. Interestingly, it was shown that there is favorable charge-controlled switchable CH₄ storage on Al(B)-, Al(N)- and C(B)-BNNSs. According to the results, the CH₄ molecule can be effectively detected by Al(N)-BNNS. However, the more E_ads, flatness of the adsorbent sheet, and feasibility of synthesize turns the C(B)-BNNS to a promising material for CH₄ storage. The atom in molecules (AIM) methodology indicates that interaction of CH₄ with Al and C atoms in the mentioned systems is more effective, correlating with the more E_ads seen for these systems.