Self-supporting NiFe LDH-MoSx integrated electrode for highly efficient water splitting at the industrial electrolysis conditions

Developing effective and practical electrocatalyst under industrial electrolysis conditions is critical for renewable hydrogen production. Herein, we report the self-supporting NiFe LDH-MoSx integrated electrode for water oxidation under normal alkaline test condition (1 M KOH at 25 degrees C) and simulated industrial electrolysis conditions (5 M KOH at 65 degrees C). Such optimized electrode exhibits excellent oxygen evolution reaction (OER) performance with overpotential of 195 and 290 mV at current density of 100 and 400 mA.cm(-2) under normal alkaline test condition. Notably, only overpotential of 156 and 201 mV were required to achieve the current density of 100 and 400 mA center dot cm-2 under simulated industrial electrolysis conditions. No significant degradations were observed after long-term durability tests for both conditions. When using in two-electrode system, the operational voltages of 1.44 and 1.72 V were required to achieve a current density of 10 and 100 mA center dot cm-2 for the overall water splitting test (NiFe LDH-MoSx/INF || 20% Pt/C). Additionally, the operational voltage of employing NiFe LDH-MoSx/INF as both cathode and anode merely require 1.52 V at 50 mA center dot cm-2 at simulated industrial electrolysis conditions. Notably, a membrane electrode assembly (MEA) for anion exchange membrane water electrolysis (AEMWEs) using NiFe LDH-MoSx/INF as an anode catalyst exhibited an energy conversion efficiency of 71.8% at current density of 400 mA center dot cm-2 in 1 M KOH at 60 degrees C. Further experimental results reveal that sulfurized substrate not only improved the conductivity of NiFe LDH, but also regulated its electronic configurations and atomic composition, leading to the excellent activity. The easy-obtained and cost-effective integrated electrodes are expected to meet the large-scale application of industrial water electrolysis. (c) 2021, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

The self-supporting NiFe LDH-MoSx integrated electrode shows excellent performance for water oxidation under normal alkaline and simulated industrial electrolysis conditions, indicating its potential for large-scale industrial water electrolysis applications.