Exploring the adsorption and sensing behavior of the M-N-x-B36-x (M=Fe, Ni, and Cu; x=0, 3) bowl-shaped structures upon CO, NO, O-2, and N-2 molecules: A first-principles study

摘要

Designing a novel metal-doped material is the abiding quest to remove toxic gases from the atmosphere using sensors based on 2D nanomaterials. Experimental observation of the finite-size of B-36 borophene on one side and theoretical investigation of the potential of B-36 as support for transition metals (Sc-Zn) on the other side, motivated this study to explore the electronic and chemical properties of B-36 as support for M = Fe, Ni, and Cu atoms towards the adsorption of O-2, N-2, NO, and CO molecules. In addition, the N-doped configuration as a result of the substitution of three N atoms with three B atoms in the central ring of B-36 moiety of the M B-36 (M = Fe, Ni, and Cu) clusters to improve their gas sensing behavior is also considered. It is found that, M B-36 clusters can bear their stability upon N-doping. Also, the impact of N-doping on the electronic structure of the M B-36 (M = Fe, Ni, and Cu) clusters before and after gas adsorption is discussed by analyzing the adsorption energy (E-ads), the change of HOMO-LUMO gap (E-g), and density of state (DOS) plots. Among the six studied clusters, namely M-NxB36-x (M = Fe, Ni, and Cu; x = 0, 3), it is revealed that Cu-B-36, Fe-N-3-B-33, Ni-N-3-B-33, and Cu-N-3-B-33 clusters could be recommended as a promising gas sensing material for the O-2, CO, NO, and N-2 gases, respectively. The Eads for the most stable configurations were calculated to be in the range of -0.32 to -3.31 eV for O-2, N-2, NO, and CO adsorption over M-N-x-B36-x clusters. Also, Eg of Fe-N-3-B-33 and Ni-N-3-B-33 clusters significantly reduces the Eg (in the range of 15-36%). Thus, the electrical conductivity of Fe-B-36 and Ni-B-36 clusters is meaningfully increased by N-doping toward CO and NO adsorption. It is expected that the potential of the M-N-x-B36-x clusters in the gas sensing can provide a new route to design boron-based gas sensors for gas detection.