Enhanced electrocatalytic performance for oxygen evolution reaction via active interfaces of Co₃O₄arrays@FeO/Carbon...

Oxygen evolution reaction (OER) is a necessary procedure in various devices including water splitting and rechargeable metal-air batteries but required a higher potential to improve oxygen evolution efficiency due to its slow reaction kinetics. In order to solve this problem, a heterostructured electrocatalyst (Co₃O₄@FeO/CC) is synthesized by deposition of iron oxides (FeO) on carbon cloth (CC) via plasma-enhanced atomic layer deposition, then growth of the cobalt oxide (Co₃O₄) nanosheet arrays. The deposition cycle of FeOon the CC strongly influences thein situgrowth and distribution of Co₃O₄nanosheets and electronic conductivity of the electrocatalyst. Owing to the high accessible and electroactive areas and improved electrical conductivity, the free-standing electrode of Co₃O₄@FeO/CC with 100 deposition cycles of FeOexhibits excellent electrocatalytic performance for OER with a low overpotential of 314.0 mV at 10 mA cm^-2and a small Tafel slope of 29.2 mV dec^-1in alkaline solution, which is much better than that of Co₃O₄/CC (448 mV), and even commercial RuO₂(380 mV). This design and optimization strategy shows a promising way to synthesize ideally designed catalytic architectures for application in energy storage and conversion.