Strongly Coupled Interface Structure in CoFe/Co3O4 Nanohybrids as Efficient Oxygen Evolution Reaction Catalysts

Abstract The quest for developing electrochemical energy‐storage and ‐conversion technologies continues to be a great impetus to develop cost‐effective, highly active, and electrochemically stable electrocatalysts for overcoming the activation energy barriers of the oxygen evolution reaction (OER). Co 3 O 4 nanocrystals have great potential as OER catalysts, and research efforts on improving the catalytic activity of Co 3 O 4 are currently underway in many laboratories. Herein, CoFe layered double hydroxide (LDH) nanosheets were directly grown on the active Co 3 O 4 substrate to form nanohybrid electrocatalysts for OER. The CoFe LDH/Co 3 O 4 (6:4) nanohybrid exhibited superior catalytic performance with a low overpotential and a small Tafel slope in alkaline solution. The outstanding performance of the CoFe LDH/Co 3 O 4 (6:4) nanohybrid was primarily owing to the synergistic effects induced by the strongly coupled interface between CoFe LDH and Co 3 O 4 ; this feature enhanced the intrinsic OER catalytic activity of the nanohybrid and favored fast charge transfer. Compared with other Co 3 O 4 ‐based catalysts, the nanohybrid shows advantages and offers a feasible avenue for improving the activity of Co 3 O 4 ‐based catalysts.