This study investigates the energy efficient and novel BaS3:La2S3:PrS1.7 nanocomposite chalcogenide system synthesized using a single source precursor technique. The prepared metallic sulphide was marked by narrow band gap of 3.6 eV and 17.39 nm average crystallite size. Functional group analysis indicated the presence of various bonds inclusive of the metal sulphide bond. Morphologically, these nano-composite chalcogenide was expressive of the irregular shaped particles arranged in the form of agglomerates. The decomposition pattern of this chalcogenide took place in two steps shown by the thermal gravimetric analysis recorded in the range of 0–800 °C. The electrochemical charge-storing behavior was evaluated. According to cyclic voltammetric results in 1 M KOH, the fabricated electrode demonstrated favorable charge storage capabilities with a specific capacitance of 776.36 F g−1. This implies that the electrode has a large amount of potential for storing energy. Additionally, the impedance studies showed that this electrode had a specific power density of 7417.69 W kg−1 and a Rs = 1.03 Ω. The OER overpotential and Tafel slope values are 457 mV and 78 mV/dec, respectively, while electrode produced a Tafel slope of 200 mV/dec and a HER overpotential value of 233 mV.