Construction of three-dimensional hierarchical flower-like M(OH)(OCH3) (M = Co and Cu) microspheres for high efficiency electrocatalytic oxygen evolution

Abstract

The slow kinetics of the oxygen evolution reaction hinders the efficiency of water decomposition, so it is crucial to develop noble metal-free electrocatalysts for the efficient decomposition of water via the oxygen evolution reaction (OER) in alkaline electrolytes. In this study, flower-like structured hydroxides grown in situ, consisting of ultrathin nanosheets stacked on Fe Foam (FF), were prepared by a one-step hydrothermal method for an efficient electrocatalytic oxygen evolution reaction. M(OH)(OCH₃) (M = Co and Cu) requires only a low overpotential of 270 mV and 379 mV for the OER, to provide 20 mA cm⁻² and 100 mA cm⁻² current densities, respectively. With the synergistic effect of Co²⁺ and Cu²⁺, the adsorption capacity of the intermediate OH* and the conductivity are improved, and the structural surface reconstruction is promoted by methoxide. In this work, the structure of FF-based electrocatalysts was modulated by the introduction of Co²⁺ and Cu²⁺ and the formation of methoxy anions, which improved the catalytic activity of the catalysts.