Synthesis and comparison of amorphous and crystalline zinc molybdate by an electrochemical evaluation for supercapacitor application

• ZnMoO 4 synthesized in situ through electrochemical method . • The Crystalline ZnMoO 4 had better electrochemical properties than Amorphous ZnMoO 4 . • Both Crystalline and Amorphous ZnMoO 4 illustrated good Cycle stability. • The mechanisms of Energy Storage were pseudo-capacitance. This study explores the synthesis and electrochemical performance of amorphous and crystalline zinc molybdate (ZnMoO 4 ) as supercapacitor electrode materials. ZnMoO 4 was synthesized via in situ electrochemical deposition on nickel foam using sodium molybdate and zinc nitrate. Structural and morphological characteristics were analyzed using XRD, FTIR, Raman spectroscopy, ultraviolet–visible spectroscopy (UV–Vis), and FE-SEM. Electrochemical performance was evaluated in 6 M KOH using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). Crystalline ZnMoO 4 exhibited a 21 % higher specific capacitance and superior cycling stability, retaining 97.22 % of its capacitance after 1000 cycles, compared to 94.6 % for the amorphous counterpart. The enhanced performance is attributed to higher crystallinity, lower resistance, and improved ion transport. A pseudocapacitive energy storage mechanism was confirmed. These findings highlight crystalline ZnMoO 4 as a promising electrode material for high-performance supercapacitors, emphasizing the role of crystallinity in optimizing energy storage.