Exploring the adsorption and sensing behavior of the M-Nx-B36-x (M=Fe, Ni, and Cu; x=0, 3) bowl-shaped structures upon CO, NO, O2, and N2 molecules: A first-principles study

Abstract

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-N x -B 36-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 E ads 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 -B 36-x clusters. Also, E g of Fe–N 3 –B 33 and Ni–N 3 –B 33 clusters significantly reduces the E g (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 -B 36-x clusters in the gas sensing can provide a new route to design boron-based gas sensors for gas detection. • O 2 , N 2 , NO, and CO adsorption on M − B 36 (M = Fe, Ni, and Cu) clusters has been investigated. • The effect of N-doing on the O 2 , N 2 , NO, and CO adsorption is also studied. • The N-doping increases the sensing behavior of metalized borophene. • Boron-based sensors can be applied in gas separation.