Investigation on synthesis and characterization of pyramidal shaped transition metals chalcogenide novel molybdenum nickel selenide (MoNiSe ₄ ) nanomaterial and enhanced electrochemical performance of the electrode for supercapacitor appli

The novel pyramidal-shaped ternary molybdenum nickel selenide (MoNiSe₄) nanomaterial was successfully synthesized using a solvothermal technique for the first time. The structural, optical and electrochemical properties of the synthesized sample were analyzed through XPS, XRD, UV-visible spectroscopy, Fourier Transform infrared (FTIR), field emission scanning electron microscope (FESEM) and EDX analyses. The XRD pattern revealed a distinct shift of the main diffraction peaks toward lower angle side compared to pure MoSe₃, validating the effective incorporation of nickel and the formation of the MoNiSe₄phase with an average crystallite size of 44 nm. The optical band gap of the material was estimated as 1.41 eV. FTIR spectra confirmed the presence of relevant metal-selenide bonds and its functional groups. Morphological analysis by FESEM revealed a pyramidal shape with triangular surfaces featuring sharp edges and distinct facets that reflect its high crystallinity. Elemental analysis through energy dispersive x-ray spectroscopy validated the stoichiometric composition of Mo, Ni and Se, whereas XPS analysis confirmed the oxidation states as Mo⁶⁺, Ni²⁺and Se^2-, further supporting the formation of the MoNiSe₄phase. Electrochemical analysis demonstrated superior supercapacitive characteristics of the MoNiSe₄electrode. Cyclic voltammetry exhibited a pseudocapacitive nature with specific capacitances of 304 F g^-1and 161 F g^-1at the scan rates of 50 and 100 mV s^-1respectively. Galvanostatic charge-discharge studies showed remarkable cycling stability with good capacitance retention even after 1500 cycles. The calculated specific capacitance, energy density and power density after 1500 cycles were 5695 × 10^-5F g^-1, 285 × 10^-9Wh kg^-1and 24 × 10^-3W kg^-1respectively. The Nyquist and Bode plots indicated ideal capacitive and pseudocapacitive behavior, confirming the efficient charge storage performance of the electrode. Overall, the MoNiSe₄demonstrates strong potential as a highly effective electrode material for advanced supercapacitor applications.