Ni Foam-Supported Ni Nanoclusters for Enhanced Electrocatalytic Oxygen Evolution Reaction

Developing oxygen evolution reaction (OER) electrocatalysts is essential to accomplish viable CO 2 and water electrolysis. Herein, we report the fabrication and OER performance of Ni-foam (NF)-immobilized Ni 6 nanoclusters (NCs) (Ni 6 /NF) prepared by a dip-coating process. The Ni 6 /NF electrode exhibited a high current density of 500 mA/cm 2 for the OER at an overpotential as low as 0.39 V. Ni 6 /NF exhibited high durability in an alkaline solution without corrosion. Electrokinetic studies revealed that OER can be easily initiated on Ni 6 NC with fast electron-transfer rates. Finally, we demonstrated stable CO 2 -to-CO electroreduction using an NC-based zero-gap CO 2 electrolyzer operated at a current density of 100 mA/cm 2 and a full-cell potential of 2.0 V for 12 h.