A High-Nickel Nanoflake Catalyst Based on NiFe-LDH and its Application in Efficient Monolithic Water Decomposition

Abstract

As the potential of hydrogen as a clean energy source continues to be explored, water electrolysis has emerged as a crucial method for producing high-purity hydrogen. In this study, nickel-iron layered double hydroxide (NiFe-LDH) catalysts were successfully synthesized on nickel foam substrates using an “etching + electrodeposition” strategy, with performance significantly enhanced through optimization of the electrodeposition process. The Ni₉@NiFe-LDH/NF catalyst demonstrated outstanding catalytic activity, exhibiting hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) overpotentials of 172.53 mV and 239.31 mV, respectively, at a current density of 100 mA cm^− 2 in 6 M KOH solution. Tafel slope and electrochemical impedance spectroscopy (EIS) analyses revealed rapid electron transfer kinetics and low charge transfer resistance. Long-term stability tests confirmed that the catalyst displayed minimal voltage decay over 10 h, indicating excellent durability. Furthermore, in a two-electrode electrolyzer test conducted at 80 °C, the catalyst required only 1.53 V to achieve a current density of 100 mA cm^− 2. This study presents a low-cost, highly efficient, bifunctional catalyst for water electrolysis, offering promising potential for both optimization and commercial application.