Bifunctional TeS/TeP2O7 Nanocomposite for Enhanced Energy Storage and Hydrogen Evolution

Abstract

Finding cost-effective and efficient nanomaterials to address the energy crisis is a significant challenge for energy production and storage technologies. Herein, tellurium-based sulfide (TeS) and phosphate (TeP₂O₇) as well as their nanocomposite (TeS/TeP₂O₇) are prepared via a solvothermal process. The structure of these TeS and TeP₂O₇ based nanomaterials are characterized by XRD, SEM, EDX, TEM, and HRTEM, while their electrochemical analysis involves cyclic voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry. The synthesized materials exhibit a large surface area and porous structure, forming spherical nanoflowers with petal thicknesses of about 20–25 nm, which enables boosting the electrochemical performance. The prepared electrode of the TeS/TeP₂O₇ active material shows redox behavior and a noticeable improvement in specific capacitance (C_s) of 1552.2 Fg^–1 at 1 Ag^–1 calculated from galvanostatic charge–discharge (GCD) measurements. These nanocomposites also show excellent cyclic stability with capacity retention of 91.5% after 5000 GCD cycles. In addition to its energy-storage capabilities, the TeS/TeP₂O₇ nanocomposite exhibits exceptionally improved electrocatalytic performance with lower HER overpotential (281 mV) and Tafel slope (44 mVdec^–1) and also higher H₂ production rate (197 μmolh^–1g^–1). The spherical nanoflowers of TeS/TeP₂O₇ highlight the material’s potential for dual applications in supercapacitor electrodes as well as efficient catalysts for hydrogen production.