Anodic electrodeposition of PbO2 on ATO/Ti with simultaneous doping of F, Co, and Fe as super-hydrophilic, highly active, and durable electrocatalyst for oxygen evolution reaction in acidic solution

Abstract

The PbO2-based electrocatalysts were synthesized on antimony-doped tin oxide (ATO)/Ti substrate by anodic electrodeposition for oxygen evolution reaction (OER) in acidic media. Different additives, such as fluorine, iron, and cobalt ions, were used to modify the PbO2 performance for enhancement within the electrocatalytic stability and activity. The water contact angle (WCA) measurements showed that after activating the electrodes, the angles ranged from 8° to 12.5° (depending on the dopants type and amount). Fe and Co doping in the electrode led to a reduction of the anodic Tafel constant from 253 for PbO2-F to 198 and 207 mV.dec−1, respectively. Also, PbO2-F-Fe-Co exhibited the lowest overpotential at 10 mA.cm−2 (η10 = 0.307 V), which was incredibly reduced compared to the PbO2-F electrode (η10 = 0.637 V). An accelerated lifetime test (ALT) at an applied current density of 2.5 A.cm−2 reported an increase of 161 h (ca. four times) in the life of the F, Co, and Fe tri-doped lead dioxide compared to the undoped one. In addition, X-ray diffraction (XRD) along with microscopic, and electrochemical analyzes were performed after 10,000 voltammetric cycles to comprehend the deactivation mechanisms of the PbO2-F-Fe-Co electrode which was the most stable among all deposited electrodes. The results demonstrated that the PbO2-F-Fe-Co electrocatalyst can be a highly efficient and durable alternative to noble metal-based electrocatalysts in OER and provided valuable insights into effective and sustainable electrocatalysts.