Enhanced hyroxyl adsorption capacity of NiFeLDH@NiCoHPi boosts water oxidation in anionic exchange membrane water electrolysis

Abstract

Improvement in the gradual pace of the oxygen evolution process is significantly required to increase the efficiency of the anion exchange membrane water electrolysis (AEMWE) for the industrial-scale hydrogen production. In this study we fabricated the layer-over-layer heterostructure of the nickel iron layered double hydroxide (NiFeLDH) and nickel cobalt hydrogen phosphate (NiCoHPi), with the highly disordered lattice structure onto the surface. The fabrication of the defect rich NiCoHPi layers over NiFeLDH was implemented by the electrodeposition process. The defect rich surface tremendously enhances the hydroxyl adsorption capacity of the NiFeLDH@NiCoHPi catalytic structure and boost the water oxidation reaction. The catalyst demonstrated the overpotential of the 264 mV to drive the current density of 20 mA cm-2 and demonstrate prolonged stability by maintaining the high current density of 200 mA cm-2 for continuous100 h. The catalyst was tested as an anode in the AEMWE cell, for NiFeLDH@NiCoHPi at 60 degrees C, 1.62 V of the potential is required to achieve the high current density of 1A cm-2. The study focused on improving the hydroxyl adsorption capability of the NiFeLDH-based heterostructure for the enhanced water oxidation process.