Enhancing the interaction between CO and single layer black phosphorous via transition metals impurities and external electric field: a theoretical study

Abstract

A systematic theoretical study based on density functional theory has been performed to explore the interaction features of CO molecule and metal-doped single layer black phosphorous (BP). Electronic structure calculations were carried out using a PBE exchange functional in conjugation with a valence double-zeta polarized/diffused basis set. To investigate the effect of impurities on the adsorption potential of the system toward CO molecules, selected transition metals (Sc, Ti, V, Co and Ni) were doped in BP layer. The results showed that while the pristine BP layer was not a superior sorbent for CO molecule and applicable for using in CO sensor devices, the calculated adsorption energies for CO/doped BPs were found to be in the range of 0.121–0.395 eV which proved the weak interaction between CO and metal doped BPs. Since the effect of imposing an electric field on the efficiency of low-dimensional systems is to be studied, we applied external electric fields in the range of 0.001–0.01 au for all of the systems. The adsorption energies were found to be as 0.153, 2.089, 0.990, 0.190, 0.883 and 0.807 eV for pristine, Sc, Ti, V, Co and Ni doped BP systems, respectively. For all systems the distribution of HOMO/LUMO, DOS and PDOS graphs were discussed before and after gas adsorption. Our results suggested that due to the high value of adsorption energy, Sc-BP may be used for CO molecule removal applications while V-BP can be applied in CO sensor devices because of a significant change of gap of energy after CO adsorption.