Rapid Synthesis of Nickel Molybdate Nanorods using Microwave for Hydrogen Evolution Reaction and Oxygen Evolution Reaction Electrocatalysis Applications

ABSTRACT In pursuit of efficient and cost‐effective electrocatalysts for hydrogen and oxygen evolution reactions (HER and OER), nickel molybdate (NiMoO 4 ) nanorods are synthesized using a rapid, energy‐saving microwave‐assisted method under varying powers and annealing temperatures. The resulting 1D nanorod morphology provides a high surface area and directional electron transport, enhancing active site accessibility. Structural analyses via X‐ray diffraction and X‐ray photoelectron spectroscopy confirmed high crystallinity and a favorable electronic structure. Electrochemical testing revealed that NiMoO 4 nanorods synthesized at 540 W and annealed at 350°C exhibited excellent bifunctional activity, with overpotentials of 336 mV at 10 mA cm −2 and a Tafel slope of 44.43 mV dec −1 for HER, and an overpotential of 184 mV at 10 mA cm −2 with a Tafel slope of 63.37 mV dec −1 for OER. The HER catalyst retained 130% activity after 12 h, while OER chronopotentiometry confirmed stable operation over the same period. The superior performance is attributed to the synergistic interaction between Ni and Mo species and the advantages of microwave synthesis. This study demonstrates the potential of microwave‐assisted synthesis for scalable fabrication of high‐performance, durable NiMoO 4 nanorods as bifunctional catalysts, advancing their application in sustainable and renewable energy technologies.