SDS-Assisted Morphology Regulation of NiMoO₄ for Efficient Alkaline Water Oxidation

Oxygen evolution reaction (OER) remains the primary kinetic bottleneck in alkaline water electrolysis, necessitating the development of efficient, economically viable, and earth-abundant electrocatalysts. Herein, a facile sodium dodecyl sulfate (SDS)-assisted hydrothermal strategy is employed to synthesize nanostructured NiMoO₄ electrocatalysts with tailored morphology and enhanced electrocatalytic activity. Acting as a soft-template and structure-directing agent, SDS regulates the nucleation and growth of NiMoO₄, resulting in a porous and interconnected nanostructure with abundant exposed active sites. The optimized NiMoO₄-SDS-2 electrode exhibits outstanding OER performance, requiring an overpotential of only 428.5 mV to achieve a current density of 100 mA cm^-2, together with a Tafel slope of 62.4 mV dec^-1, demonstrating accelerated reaction kinetics. Electrochemical impedance spectroscopy and double-layer capacitance analyses reveal enhanced charge-transfer capability and a larger electrochemically active surface area, while long-term durability tests confirm excellent operational stability under alkaline conditions. The enhanced catalytic performance is associated with SDS-induced morphology regulation, improved active-site accessibility, and favorable interfacial charge-transfer characteristics. This work demonstrates that surfactant-assisted soft-templating is an effective strategy for engineering high-performance NiMoO₄-based electrocatalysts and provides valuable insights into the rational design of advanced transition metal oxide catalysts for efficient and durable alkaline water oxidation.