Water Oxidation Electrocatalyzed by an Efficient Mn3O4/CoSe2Nanocomposite

Abstract

The design of efficient, cheap, and abundant oxygen evolution reaction (OER) catalysts is crucial to the development of sustainable energy sources for powering fuel cells. We describe here a novel Mn₃O₄/CoSe₂ hybrid which could be a promising candidate for such electrocatalysts. Possibly due to the synergetic chemical coupling effects between Mn₃O₄ and CoSe₂, the constructed hybrid displayed superior OER catalytic performance relative to its parent CoSe₂/DETA nanobelts. Notably, such earth-abundant cobalt (Co)-based catalyst afforded a current density of 10 mA cm^–2 at a small overpotential of ∼0.45 V and a small Tafel slope down to 49 mV/decade, comparable to the best performance of the well-investigated cobalt oxides. Moreover, this Mn₃O₄/CoSe₂ hybrid shows good stability in 0.1 M KOH electrolyte, which is highly required to a promising OER electrocatalyst.