The increasing global energy demand necessitates the development of reliable and environmentally sustainable energy storage solutionsThis study explores the enhancement of molybdenum diphosphide (MoP2)-based supercapacitor electrodes through doping with tantalum (Ta), tin (Sn), and lanthanum (La), resp.The dopants Ta, Sn and La have been chosen from transition metals, post-transition metals and rare earth elements resp. to have the comparison of electrochem. performance.A facile hydrothermal synthesis route was employed to achieve controlled nanostructure growth, and the materials were thoroughly characterized using XRD, SEM, EDX, and TEM.Electrochem. properties were investigated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochem. impedance spectroscopy (EIS) in a 2 M KOH electrolyte solutionThe doping process significantly optimized the morphol. of MoP2, forming high-surface-area nanostructures such as nanorods, nanosheets, and nanoflowers.Electrochem. anal. revealed enhanced redox activity in the doped samples.Specifically, La-doped MoP2 achieved superior performance of maximum capacitance of 1816F/g at 5 mV/s scan rate, with excellent cycling stability, retaining 92 % of its capacitance after 5000 cycles at 1 A/g.EIS results confirmed the high conductivity and improved charge transfer resistance of the La-doped sample.These findings highlight the critical role of rare earth element doping in optimizing MoP2-based electrodes for supercapacitors, outperforming transition and post-transition metal doping in terms of energy storage capabilities and stability.The La-doped MoP2 robust nanomaterial demonstrates significant potential for next-generation energy storage applications.