String ball-like SnS2/ZnTe heterostructures with improved bifunctional photo/electrocatalytic activity towards overall water splitting

Abstract

SnS₂/ZnTe nanocomposites were successfully synthesized via a two-step methodology incorporating hydrothermal techniques. The resultant nanocomposites underwent comprehensive characterization encompassing morphological, structural, and compositional aspects through the utilization of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Furthermore, the electrochemical performance of these newly synthesized nanostructures was evaluated in the absence and presence of light to ascertain their suitability for energy generation applications. In the context of the hydrogen evolution reaction (HER) against reference electrode 0.185 vs. RHE, it was observed that SnS₂/ZnTe electrodes exhibited notably low overpotentials, registering at 185 mV, along with a Tafel slope of 80 mV dec⁻¹ under visible light. These findings underscore the superior catalytic activity of SnS₂/ZnTe electrodes in the HER. Moreover, the SnS₂/ZnTe electrode demonstrated a substantially reduced overpotential of 105 mV at a current density of 10 mA cm⁻², accompanied by a Tafel slope of 47 mV dec⁻¹ under visible light, indicative of a swift and efficient performance in the oxygen evolution reaction (OER). In light of these outcomes, these nanostructures exhibit significant promise as electrode materials for applications in water splitting, thereby contributing to advancements in sustainable energy production.