Investigation of Wet-Preparation Methods of Nickel Foam For Alkaline Water Electrolysis

Abstract

Water electrolysers are multi-component systems whose performance relies on each part performing its task. A great emphasis has been placed on the development of efficient catalyst-coated electrodes, however the efficacy of the underlying substrate itself has been overlooked. This paper investigates the resulting performance of nickel foam electrodes in 1.0 M KOH after being treated in various concentrations of hydrochloric acid and sulphuric acid. The greatest performance was achieved utilising 0.50 M H2SO4 as measured by LSV, EIS and CV and ECSA, resulting in a 27% decline in series resistance relative to untreated nickel foam. The series resistance decreased continuously with acid concentration until a plateau was reached at the concentration of 0.5 M, where this trend was seen for both types of acid. Utilising these preparation methods for nickel foam electrodes can notably enhance electrode performance.

Detection of a Nickel-Oxide Nanolayer During Mild Acid Treatment of Nickel Foam and Its Effect on Alkaline Oxygen Evolution and Ammonia Oxidation Reactions

“…1 The key factors that control the electrocatalytic performance of an electrode are the electrical conductivity of the substrate itself and the extent of charge transport between the interface of the electrode surface and the deposited catalyst material (heterogeneous). 2 To make this charge/electron transport more facile, the choice of the electrode substrate plays a central role and is important in terms of its stability and activity in harsh conditions. Considering low-cost, better charge/electron mobility, high specific surface area, and superior aqueous stability, three-dimensional (3-D) nickel foam (NF) is widely used as an electrode substrate.…”

“…The electrocatalytic HER study of such acid-pretreated NF exhibited better activity when a higher acid concentration was chosen for the pretreatment. 2 In the majority of published works, after the acid treatment, NF was not characterized and the effect of acid treatment was not carefully analyzed. However, Yeo et al reported that the OER process under alkaline conditions leads to the formation of the γ-NiO(OH) phase on bulk Ni, identified through in situ Raman spectra analysis.…”

“…Numerous strategies are taken for choosing the electrode materials with better activity, including high electrochemical stability, low cost, and high catalytic efficiency . The key factors that control the electrocatalytic performance of an electrode are the electrical conductivity of the substrate itself and the extent of charge transport between the interface of the electrode surface and the deposited catalyst material (heterogeneous) . To make this charge/electron transport more facile, the choice of the electrode substrate plays a central role and is important in terms of its stability and activity in harsh conditions.…”

“…To make this charge/electron transport more facile, the choice of the electrode substrate plays a central role and is important in terms of its stability and activity in harsh conditions. Considering low-cost, better charge/electron mobility, high specific surface area, and superior aqueous stability, three-dimensional (3-D) nickel foam (NF) is widely used as an electrode substrate. , The 3D network structure also gives a better mass loading of the catalyst compared to that of a flat electrode surface . Additionally, the advantages are easy mass transfer, better analyte/electrolyte adsorption, gas desorption, high mechanical strength, and better current collector with low electrical resistivity …”

“…Different pretreatments or washings of raw NF can be found in the literature, and these include the use of different acids like HCl, H 2 SO 4 , HClO 4 , and HNO 3 to eradicate organic contamination as well as the oxide layer (Table S1). , However, the concentration of used acids, washing time, sonication time, and drying conditions must be chosen carefully. Otherwise, it may result in the formation of a nonconductive oxide/hydroxide layer or nanoparticle via surface etching or corrosion during pretreatment and it may influence the electrocatalytic activity.…”