Methane gas adsorption and detection using the metal-decorated blue phosphorene

Abstract

Previous studies showed that the performances of two-dimensional materials as gas sensor can be effectively improved through the assistance of metal atoms. We study the adsorption energies, charge transfers and electronic structures of the blue phosphorene (BP) adsorbing metal atoms (Au, Ag, Cu, Co, Fe and Mn) and then adsorbing methane (CH4) gas molecule. The metal-decorated BP can be used as an excellent CH4 gas adsorption material, and the adsorption capacity is not easily disturbed by the magnetic field. The transfer charges between metal atoms and BP will induce the new energy bands to modulate the band structure of BP effectively. In the absence of a magnetic field, CH4 adsorption hardly change the band structures of BP decorated by six metal atoms. However, the CH4 adsorption can modulate the spin-polarizedbandgaps and magnetic moments of Co, Fe and Mn decorated BP obviously in the present of a magnetic field. In particular, the spin-down band gap of Fe-decorated BP would be reduced by two-third and the corresponding magnetic moment of Fe-decorated BP also decreases from 2.455 µB to 2.229 µB after CH4 adsorption. So, Fe-decorated BP is expected to be used as a material for high sensitivity CH4 gas detection.