Strongly Coupled Interface Structure in CoFe/Co 3 O 4 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). 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.
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