F-doped Co3O4/carbon composite catalyst for alkaline oxygen evolution

Abstract

Electrocatalytic water splitting represents a sustainable method for hydrogen production. However, the oxygen evolution reaction (OER) at the anode often exhibits sluggish kinetics and low energy conversion efficiency. This paper describes the regulation of the electronic structure of the Co₃O₄/carbon composites through anion doping. Specifically, F-doped carbon substrates are combined with ZIF-67, wherein the active component Co₃O₄ is encapsulated within the framework formed by ZIF-67. The two-dimensional (2D) nanosheet structure derived from ZIF-67 provides a large specific surface area and exposes abundant active sites. More importantly, fluorine (F) doping modulates the electronic structure of Co₃O₄/carbon@NF, activates the lattice oxygen mechanism (LOM), and promotes surface reconstruction into highly active cobalt oxyhydroxide (CoOOH), thereby significantly enhancing OER performance. Furthermore, F-Co₃O₄/carbon@NF exhibits a more favorable d-band center, which optimizes the adsorption energy of key intermediates and accelerates reaction kinetics. The resulting nanocomposite catalyst, F-Co₃O₄/carbon@NF, displays exceptional OER performance, requiring only an overpotential of 201 mV at 100 mA cm⁻². This catalyst maintains its performance over 24 hours of continuous operation, with the catalytic activity surpassing many similar catalysts.