Theoretical insights into the structural, relative stable, electronic, and gas sensing properties of PbnAun (n = 2–12) clusters: a DFT study

Abstract

Recently, Au-based clusters have been provoking great interest due to their potential applications in nanotechnology. Herein, the structural, relative stable, electronic, and gas sensing properties of Pb_nAu_n (n = 2–12) clusters were systematically investigated using density functional theory together with scalar relativistic pseudopotential. The ground state structures, average binding energies, dissociation energies, second order energy differences, HOMO–LUMO gaps, and average Mulliken charges of Pb_nAu_n (n = 2–12) clusters were calculated. The results revealing that the Pb_nAu_n (n = 4, 6, and 8) clusters are more relatively stable than their neighboring clusters. Furthermore, charges are always transferred from the Pb atoms to Au atoms based on Mulliken charge analysis. Furthermore, through the investigations of CO or NO molecule adsorption onto Pb_nAu_n (n = 4, 6, and 8) clusters, it is found that CO or NO molecule can chemisorb on those clusters with high sensitivity, and the charges are transferred from Pb_nAu_n (n = 4, 6, and 8) clusters to the gas molecules. According to the analysis of the electric conductivity, Pb_nAu_n (n = 4, 6, and 8) clusters can be served as potential gas sensors in CO and NO molecules detection.