Pulse electrodeposition of CoFe thin films covered with layered double hydroxides as a fast route to prepare enhanced catalysts for oxygen evolution reaction

Abstract

A novel, ultra-fast, and one-step method for obtaining an effective catalyst for oxygen evolution reaction is proposed. The procedure consists in direct electrodeposition, in a free-nitrate bath, of CoFe alloy films covered with layered double hydroxides (LDH), by potentiostatic mode, in continuous or pulsed regime. The catalyst is directly formed on glassy carbon substrates. The best-prepared catalyst material reveals a mixed morphology with granular and dendritic CoFe alloy covered with a sponge of CoFe-LDH containing a Cl interlayer. An overpotential of η10 mA = 286 mV, with a Tafel slope of 48 mV dec−1, is obtained for the OER which displays the enhanced properties of the catalyst. These improved results demonstrate the competitiveness and efficacy of our proposal for the production of OER catalysts.