Metal-Hydroxide and Gold-Nanocluster Interfaces: Enhancing Catalyst Activity and Stability for Oxygen Evolution Reaction

By engineering the interaction between the transition metal ions (M = Mn2+, Co2+, and Ni2+) and the nanorod-shaped assemblages of Au nanoclusters (AuNCs), a series of tubular AuNCs@M(OH)(2) core-shell nanocomposites are produced in which numerous AuNCs are embedded beneath a thin layer of metal hydroxide with thickness below 4 nm and where the AuNCs within the same assemblage are partially connected with each other. Because of the synergistic effects from the abundant presence of the AuNCs-M(OH)(2) interfaces, the AuNCs@M(OH)(2) (M = Co and Ni) nanocomposites demonstrate evidently enhanced activity for oxygen evolution reaction (OER) in alkaline condition. Overpotentials of 0.350 and 0.375 V have been obtained at the current density of 10 mA cm(-2) in 0.1 M KOH for the AuNCs@Co(OH)(2) and AuNCs@Ni(OH)(2), respectively. And at the overpotential of 0.42 V, the current density of AuNCs@M(OH)(2) (M = Co and Ni) nanocomposites is more than 10 times of those generated by their respective metal hydroxides. Compared with monophasic transition metal hydroxides, the AuNCs@M(OH)(2) nanocomposites, especially the AuNCs@Ni(OH)(2), possess excellent OER catalytic stability.