Carbon cloth supporting spinel CuMn0.5Co2O4 nanoneedles with the regulated electronic structure by multiple metal elements as catalysts for efficient oxygen evolution reaction

Abstract

Developing transition metal oxide catalysts to replace the noble metal oxide catalysts for efficient oxygen evolution reaction (OER) is essential to promote the practical application of water splitting. Herein, we designed and constructed the carbon cloth (CC) supporting spinel CuMn_0.5Co₂O₄ nanoneedles with regulated electronic structure by multiple metal elements with variable chemical valences in the spinel CuMn_0.5Co₂O₄. The carbon cloth not only provided good conductivity for the catalytic reaction but also supported the well-standing spinel CuMn_0.5Co₂O₄ nanoneedles arrays with a large special surface area. Meanwhile, the well-standing nanoneedles arrays and mesoporous structure of CuMn_0.5Co₂O₄ nanoneedles enhanced their wettability and facilitated access for electrolyte to electrochemical catalysis. Besides, the regulated electronic structure and generated oxygen vacancies of CuMn_0.5Co₂O₄/CC by multiple metal elements improved the intrinsic catalytic activity and the durability of OER activity. Profiting from these merits, the CuMn_0.5Co₂O₄/CC electrode exhibited superior OER activity with an ultralow overpotential of 189 mV at the current density of 10 mA⋅cm^-2 and a smaller Tafel slope of 64.1 mV⋅dec^-1, which was competitive with the noble metal oxides electrode. And the CuMn_0.5Co₂O₄/CC electrode also exhibited long-term durability for OER with 95.3% of current retention after 1000 cycles. Therefore, the competitive OER activity and excellent cycling durability suggested that the CuMn_0.5Co₂O₄/CC electrode is a potential candidate catalyst for efficient OER.