Enhancing Hydrogen Evolution Efficiency in Alkaline Water Electrolysis Using Optimized Raney Nickel Coatings on Stainless Steel Electrodes

Abstract

Hydrogen, as a clean and high-energy-density fuel, holds immense promise for future energy systems. The aim of this study is to enhance the efficacy and durability of hydrogen evolution reactions (HER) in alkaline water electrolysis by optimizing Raney Nickel coatings on stainless steel electrodes. This work aims to reduce costs and improve the performance of electrolysis systems, making hydrogen production more feasible for large-scale applications. The study involved the electrodeposition of Raney Nickel on stainless steel substrates using a modified Watt’s bath. The pretreatment process included degreasing, acid pickling, and Nickel Strike coating to prepare the electrode surface. Functional coatings were applied in a solution containing NiSO4, NiCl2, H3BO3, and ZnCl2 at 50°C. The obtained coating substrates were characterized both chemically and morphogically by XRF analysis and confocal laser scanning microscopy. The performance of the electrodes was evaluated through electrochemical measurements, determining the electrochemical surface area (ECSA) and overpotentials for HER and oxygen evolution reactions (OER) The optimized Raney Nickel coatings, referred to as Raney 2, demonstrated a significant improvement in both HER and OER performance compared to traditional coatings. The Raney 2 coating exhibited a threefold increase in ECSA. The accelerated aging tests showed that the Raney 2 coating outperformed Raney 1, with lower peak voltages and improved stability over time. The roughness factor of the Raney 2 electrode is higher, indicating has an extensive reactive surface area. Furthermore, the study confirmed that the incorporation of elements from the 316-grade stainless steel counter-electrode, such as iron, contributed to enhanced catalytic activity, particularly for OER. These findings suggest that the modified coating process can significantly extend the operational life and efficiency of electrolysis electrodes. This work presents a novel approach to enhancing the performance of Raney Nickel coatings by incorporating a 316-grade stainless steel counter-electrode during deposition, which has not been extensively explored in existing literature. The resulting hybrid coating demonstrates superior electrochemical performance and durability, offering a cost-effective solution for improving alkaline water electrolysis systems. This advancement can significantly contribute to the development of more sustainable and efficient hydrogen production technologies.