Enhanced oxygen evolution reaction and durability of carbon dot-anchored nickel-iron oxyhydroxide electrodes for alkaline water electrolysis at high current densities

This study presents a nickel-iron layered double hydroxide (Ni₁₋ₓFeₓOOH-LDH) catalyst anchored with carbon dots (CD), optimized for high current density alkaline water electrolysis. The catalyst employs a Ni:Fe ratio of 0.6:0.4, which balances catalytic activity and stability. Fe enhances the lattice oxygen mechanism (LOM) by promoting oxygen vacancy formation, while Ni supports structural integrity and facilitates electron transfer. Carbon dots improve conductivity, protect the electrode from corrosion, and stabilize active sites. The interplay among Ni, Fe, and C creates a robust electron transfer network, enabling efficient O₂ evolution while suppressing inactive intermediates. As a result, the CD@Ni₀.₆Fe₀.₄OOH/CP electrode achieves a low overpotential of 1.47 V at 10 mA/cm2 and maintains stable overpotentials of 1.64 V and 1.98 V at 100 and 500 mA/cm2, respectively, over 10 days of continuous operation. These findings highlight the potential of this catalyst design to address key challenges in oxygen evolution reaction (OER) performance and durability, paving the way for scalable and efficient energy conversion technologies.