Hydrothermally grown g-C3N4 incorporated MnMoO4 blade-like structure for symmetric supercapacitor applications

To improve the electrochemical performance of the electrode material, challenges such as low electrical conductivity, limited rate capability and unstable redox reactions can be addressed by elemental doping. This study presents the fabrication of g-C 3 N 4 (g-CN) doped MnMoO 4 (MMO) nanorods as an efficient electrode material via a facile one-pot hydrothermal method. X-ray diffraction (XRD) analysis confirms the formation of a highly crystalline MMO phase with an average crystallite size of ∼25 nm, while transmission electron microscopy (TEM) images reveal well-defined nanorods with homogeneous dispersion. The interplanar spacing obtained from TEM analysis agrees with XRD results, validating the crystalline nature of the composite. Thermogravimetric analysis (TGA) indicates good thermal stability, with 83% weight retention up to 800 °C.X-ray photoelectron spectroscopy (XPS) results reveal the presence of reversible Mn 2+ /Mn 3+ and Mo 6+ /Mo 4+ redox couples, contributing significantly to pseudocapacitive behavior. The g-CN@MMO nanorods coated on Ni foam exhibits a high specific capacitance of 578 F /g at 1 A /g in 3 M KOH. The assembled symmetric supercapacitor delivers an energy density of 11 Wh /kg at a power density of 7270 W /kg and retains 84% capacitance after 10,000 cycles, demonstrating excellent electrochemical performance.