Design the Synergy of Rare Earth Metal Based Ce2S3@Ni3S2 Hybrid Electrode Materials for Hydrogen Evolution and Supercapacitor Application: Dual Excellence

The enhancing need for efficient energy storage and conversion devices demonstrates the crucial need for electrode materials with dual excellence. Conversely, attaining simultaneous optimization of supercapcitor performance and hydrogen evolution reaction (HER) activity remains a challenge due to limitations of material. This study reported the synthesis of pure nickel sulfide (Ni₃S₂) and (3% and 5%) cerium-doped nickel sulfide (Ce₂S₃-doped Ni₃S₂) nanomaterials with micro-emulsion-mediated hydrothermal approach for dual-excellence in supercapcitor and hydrogen evolution reactions (HER). The synthesized materials were characterized via UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The SEM analysis illustrated aggregated globular morphology of the prepared nanomaterials. The electrochemical performance confirmed exceptional pseudocapacitive behaviour and remarkable cyclic stability of the prepared Ce-doped Ni₃S₂ materials. Cyclic voltammetry (CV) analysis displayed symmetrical behaviour, sustaining 89% stability at 3000th cycles. Similarly, galvanostatic charge-discharge (GCD) at performed at 1 A/g exposed capacitance values of 890 F/g, 978 F/g and 1106 F/g for pure Ni₃S₂, 5% Ce₂S₃-Ni₃S₂ and 3% Ce₂S₃-Ni₃S₂. Additionally, energy densities were also determined about 31.15 Wh/kg, 38.71 Wh/kg, and 34.23 Wh/kg, for pure Ni₃S₂, 3% Ce-doped Ni₃S₂ and 5% Ce-doped Ni₃S₂ respectively. Interestingly, the 3% Ce-doped Ni₃S₂ demonstrated superior cyclic stability (92% after 3000th cycles) and significant performance, illustrating its potential as a high-performance energy storage device. Moreover, the ideal concentration of cerium dopant was determined to be 3% in Ni₃S₂ in HER study, exhibited an onset potential of 0.14 V, an over potential of 71 mV at a current density of 10 mAcm^− 2, and a Tafel slope of 57 mVdec^− 1 in 2.0 M KOH, demonstrating the highest activity.

Graphical Abstract