Strongly Coupled Interface Structure in CoFe/Co3 O4 Nanohybrids as Efficient Oxygen Evolution Reaction Catalysts.

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). Co3 O4 nanocrystals have great potential as OER catalysts, and research efforts on improving the catalytic activity of Co3 O4 are currently underway in many laboratories. Herein, CoFe layered double hydroxide (LDH) nanosheets were directly grown on the active Co3 O4 substrate to form nanohybrid electrocatalysts for OER. The CoFe LDH/Co3 O4 (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/Co3 O4 (6:4) nanohybrid was primarily owing to the synergistic effects induced by the strongly coupled interface between CoFe LDH and Co3 O4 ; this feature enhanced the intrinsic OER catalytic activity of the nanohybrid and favored fast charge transfer. Compared with other Co3 O4 -based catalysts, the nanohybrid shows advantages and offers a feasible avenue for improving the activity of Co3 O4 -based catalysts.