PPy enhanced Fe, W Co-doped Co3O4 free-standing electrode for highly-efficient oxygen evolution reaction

Abstract

Electrochemical catalysts for the oxygen evolution reaction (OER) play a key role in highly-efficient water splitting and many other important energy conversion applications. Transition metal oxides are promising OER catalysts. In this work, Fe, W co-doped Co3O4 was grown on carbon fiber cloth (FeWCo3O4/CFC) and polypyrrole (PPy)/carbon fiber cloth (FeWCo3O4/PPy/CFC) through a simple anodic electrodeposition method. The FeWCo3O4/CFC free-standing electrode reached an electrocatalytic current density of 30.7 mA cm−2 at 400 mV overpotential with a Tafel slope of 177 mV dec−1. The PPy can serve as conductive binder and improve the contact between FeWCo3O4 and substrate. The resulting FeWCo3O4/PPy/CFC free-standing electrode reached an electrocatalytic current density of 36.2 mA cm−2 at 400 mV overpotential with a Tafel slope of 163 mV dec−1. The FeWCo3O4/PPy/CFC free-standing electrode shows low electric resistance and is able to catalyze OER at 10 mA cm−2 for 12 h without obvious decay under the optimized electrodeposition conditions. This study provides new insight for design and synthesis of highly-efficient OER catalyst. Graphical Abstract: [see fulltext]