Single-Step Direct Hydrothermal Growth of NiMoO₄ Nanostructured Thin Film on Stainless Steel for Supercapacitor Electrodes

We report a facile and direct growth of NiMoO₄ nanostructures on a nonreactive stainless steel substrate using a single-step hydrothermal method and investigated hydrothermal growth duration effects on morphology and electrochemical characteristics. The highest specific capacitances of 341, 619, and 281 F/g were observed for NiMoO₄ with 9, 18, and 27 h growth, respectively, at 1 A/g. Thus, grown samples preserved almost 59% of maximum specific capacitance at a high current density of 10 A/g. All samples exhibited a respectable cycling stability over 3000 charge-discharge operations. NiMoO₄ grown for 18 h exhibited 7200 W/kg peak power density at 14 Wh/kg energy density. Thus, the proposed single-step hydrothermal growth is a promising route to obtain NiMoO₄ nanostructures and other metal oxide electrodes for supercapacitor applications.