Engineering Cu2O/Cu@CoO Hierarchical Nanospheres: Synergetic Effect of Fast Charge Transfer Cores and Active Shells for Enhanced Oxygen Evolution Reaction
A novel hollow core-shell Cu2O/Cu@CoO nanospheres composed of Cu2O/Cu core and CoO shell was produced via a facile soft template method and a post-thermal annealing process. The formation of Cu2O/Cu metal/semiconductor core structure played a key role in increasing the conductivity and facilitated the fast charge transfer process during electrochemical reaction. Engineering chemical coupling of active CoO shell provided large surface roughness to the benefit of abundant adsorbed active species OH- for OER. The synergetic effect of fast charge transfer cores and active shells enhanced OER. By adjusting the raw ratio of Cu/Co to 1/2, Cu2O/Cu@CoO exhibited the lowest overpotential for 330 mV at 10 mAcm-2. This facile chemical method which coupled CoO nanoparticles with Cu2O/Cu hollow spheres would pave the way for controlling fabrication of other core-shell binary transition metal oxides heterogeneous catalysts for electrochemical applications.