Properties of hydrogen doped Cu nanowires and nanocontacts: a density-functional theory study

Using first-principles calculations based on density-functional theory, we systematically investigate the structural and electronic properties of hydrogen (hydrogen atoms and H₂ molecule) doped Cu chain nanowires and nanocontacts. Various possible configurations of Cu chain nanowires and nanocontacts doped with hydrogen impurities are considered. These Cu chain nanowires and nanocontacts are stabilized by hydrogen impurities beyond their classical breaking point. The formed metal-impurity bond is much stronger than the metal–metal bond. Upon elongation, the doped Cu chain nanowire tends to break from the remote metal–metal bond and the doped Cu nanocontact will break from metal–metal chain bond. The interaction between hydrogen impurities and Cu atoms alters the interatomic bonding and hybridization of electronic states in Cu chain nanowires and nanocontacts. Additionally, the dissociation of H₂ molecule is observed when H₂ molecule doped in Cu nanocontact, which can be used in catalytic application. (paper)