Accelerated Durability Tests of Electrostatic Spray Deposited NiFe2O4 for Renewable Energy-Powered Alkaline Water Electrolyzers

Hydrogen production by water electrolysis is of utmost significance for a clean, renewable and carbon neutral energy economy. Specifically, the integration of water electrolysis systems with renewable energy sources (RES) shows great potential. A key obstacle for RES-powered water electrolysis technology is the incorporation of intermittent and unpredictable energy production, due to which constrains stable operation of water electrolyzer resulting in the electrode degradation of OER electrocatalysts. Herein, NiFe 2 O 4 electrocatalyst was fabricated using simple and scalable electrostatic spray deposition technique. To evaluate robustness as OER electrode, the operational durability tests were carried out under three harsh dynamic operating regimes (i.e., constant, transient, and on-off). The electrode showed remarkable durability under steady state operation at constant applied voltage vs RHE and On-Off condition for about 24 hours. Furthermore, alterations in morphology and electrocatalytic performance were comprehensively investigated through the utilization of X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) measurements.