Heterogeneous bimetallic Ni(OH)2-NiMoO4/NF as an efficient HER electrocatalyst for alkaline water splitting

Abstract

Highly efficient earth-abundant electrocatalysts are of great importance for water-splitting to produce clean and renewable chemical fuel. Herein, a 1D/3D hierarchical heterostructure electrocatalyst, consisting of NiMoO₄ nanorod arrays inserted with Ni(OH)₂ nanoflowers, is delicately constructed via the hydrothermal-calcination and rapid electrodeposition method. In an alkaline solution, the obtained Ni(OH)₂-NiMoO₄/NF electrocatalyst exhibits outstanding HER activity, with a low overpotential of 90 mV at 10 mA cm⁻², a low Tafel slope of 86.9 mV dec⁻¹ as well as high stability. The unique structure increases the specific surface area and facilitates the release of air bubbles and the penetration of electrolytes. The simple synthesis process and outstanding electrocatalytic performances show great potential of Ni(OH)₂-NiMoO₄/NF to replace the noble metal-based catalysts toward the HER.