Electrodeposition of High-Surface-Area IrO2 Films on Ti Felt as an Efficient Catalyst for the Oxygen Evolution Reaction

Abstract

Under acidic conditions, IrO 2 exhibits high catalytic activity with respect to the oxygen evolution reaction (OER). However, the practical application of Ir-based catalysts is significantly limited owing to their high cost in addition to the scarcity of the metal. Therefore, it is necessary to improve the efficiency of the utilization of such catalysts. In this study, IrO 2-coated Ti felt (IrO 2 /Ti) electrodes were prepared as high-efficiency catalysts for the OER under acidic conditions. By controlling the surface roughness of the Ti substrate via wet etching, the optimum Ti substrate surface area for application in the IrO 2 /Ti electrode was determined. Additionally, the IrO 2 film that was electrodeposited on the 30 min etched Ti felt had a large surface area and a uniform morphology. Furthermore, there were no micro-cracks and the electrode obtained (IrO 2 /Ti-30) exhibited superior catalytic performance with respect to the OER, with a mass activity of 362.3 A g −1 Ir at a potential of 2.0 V (vs. RHE) despite the low Ir loading (0.2 mg cm −2). Therefore, this proposed strategy for the development of IrO 2 /Ti electrodes with substrate surface control via wet etching has potential for application in the improvement of the efficiency of catalyst utilization with respect to the OER.

Microwave-assisted synthesis of iridium oxide and palladium nanoparticles supported on a nitrogen-rich covalent triazine framework as superior electrocatalysts for the hydrogen evolution and oxygen reduction reaction

“…While for IrO x 14 @CTF750 PC two different oxidation states were confirmed from the deconvolution of the high-resolution spectrum ( Figure 2B ). The binding energies at 61.69 and 64.66 eV (doublet separation of 2.97 eV) are in good agreement with the literature for the 4f 7/2 state of Ir (+IV) and Ir (+III) which suggests a mixed valent oxide ( Hall and Sherwood, 1984 ; Pfeifer et al, 2016 ; Jürgensen et al, 2020 ; Park et al, 2020 ). According to the peak fitting, the Ir(+IV) state is present with 76 at%, and the Ir(+III) state with 24 at%.…”

3D-printed NiFe-layered double hydroxide pyramid electrodes for enhanced electrocatalytic oxygen evolution reaction

“…The obtained NiFe electrode was rinsed with DI water before drying in a convection oven at 70 °C. For comparison of electrocatalytic activity, IrO 2 was synthesized on the pyramid array by electrodeposition 50 .…”

A highly active and stable 3D dandelion spore-structured self-supporting Ir-based electrocatalyst for proton exchange membrane water electrolysis fabricated using structural reconstruction

“…We used a PTL of Ti fiber felt (BEKAERT, 2GDL08N-025) as the working electrode, a saturated calomel electrode (SCE, CHI Instruments, CHI150) as the reference electrode, and a graphite rod as the counter electrode. Prior to electrodeposition, the Ti fiber felt substrate was treated with 5 wt% oxalic acid ((COOH) 2 ·2H 2 O (Daejung, 5640-4400)) solution at 95 °C for 30 min to remove surface oxide, 22 washed with deionized water, vacuum dried, and then mounted on a home-made Teflon cell exposing an area of 1.327 cm 2 ( d = 1.3 cm). The electrolyte was prepared by dissolving 0.01 M HCl (Daejung, 4090-4400), 0.1 M NH 4 Cl (Daejung, 1060-4100), 0.3 M H 3 BO 3 (Daejung, 2036-4405), 0.05 M NiCl 2 ·6H 2 O (Wako pure chemical industry, 141-01045) and 0.02 M Na 3 IrCl 6 · x H 2 O (Sigma-Aldrich, 288160) in deionized water (DI water, 18.2 MΩ), and stirring for 30 min.…”