GQD-modified CoFe-LDH@nickel foam as a high-performance anode catalyst for anion exchange membrane water electrolysis

Abstract

The use of graphene quantum dot (GQD)-modified CoFe layered double hydroxides (GQD@CoFe-LDH), grown on nickel foam, is explored as an anode catalyst for the oxygen evolution reaction (OER) in anion exchange membrane water electrolyzers (AEMWEs). Careful tuning of GQD loading reveals that an optimal amount of GQDs induces a pronounced synergistic effect, enhancing electron transport and active site utilization while lowering the overpotential for the OER. Compared with pristine CoFe-LDH, GQD incorporation significantly reduces interfacial charge-transfer resistance, thereby enhancing OER activity. In single-cell AEMWE testing, the GQD@CoFe-LDH anode with optimal GQD loading achieves a current density of 1749 mA cm⁻² at 2.0 V, indicating a marked improvement over the unmodified CoFe-LDH. This enhancement corresponds to a 61% increase in OER performance relative to the pristine electrode. These findings underscore the effectiveness of rational GQD modification in improving both catalytic activity and corrosion resistance of CoFe-LDH electrodes, presenting a promising and cost-efficient strategy for hydrogen production via water electrolysis.