Enhancing the catalytic stability of lead dioxide electrodes for oxygen evolution reaction through α-PbO₂ lining and...

This study focuses on the synthesis of a non-noble metal-based anode electrode on a titanium substrate. Lead dioxide anodes were fabricated via electrodeposition, employing a two-step process on a tin-antimony oxide (ATO) interlayer deposited by thermal decomposition. The inner α-PbO₂ layer was electrodeposited from an alkaline solution, while the outer β-PbO₂ layer was formed from an acidic bath. To augment the catalytic properties and stability of the anode, the effects of fluorine, cobalt, copper, nickel, and iron additives were systematically investigated. Initially, 0.02 M sodium fluoride was introduced into the β-PbO₂ electrodeposition bath. Subsequently, 0.01 M solutions of cobalt, copper, nickel, and iron nitrates were added into the lead nitrate and sodium fluoride deposition solution. The phase structure, surface electronic states, and morphology of the synthesized materials were thoroughly characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FE-SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). Catalytic activity and electron transfer resistance were evaluated by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Electrode stability was assessed via chronopotentiometry (CP) and cyclic voltammetry (CV). While fluorine doping alone diminished catalytic properties, it enhanced the anode's stability. Co-doping with fluorine and iron resulted in reduced grain size and increased specific surface area. The fluorine-iron co-doped lead dioxide anode demonstrated superior catalytic performance, exhibiting a charge transfer resistance of 20 Ω cm² and an operational stability of 66 hours at a current density of 3 A cm^-2, significantly outperforming the lead dioxide anode.