An advanced PdNPs@MoS2 nanocomposite for efficient oxygen evolution reaction in alkaline media

Abstract

In response to the increasing availability of hydrogen energy and renewable energy sources, molybdenum disulfide (MoS₂)-based electrocatalysts are becoming increasingly important for efficient electrochemical water splitting. This study involves the incorporation of palladium nanoparticles (PdNPs) into hydrothermally grown MoS₂ via a UV light assisted process to afford PdNPs@MoS₂ as an alternative electrocatalyst for efficient energy storage and conversion. Various analytical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS), were used to investigate the morphology, crystal quality, and chemical composition of the samples. Although PdNPs did not alter the MoS₂ morphology, oxygen evolution reaction (OER) activity was driven at considerable overpotential. When electrochemical water splitting was performed in 1.0 M KOH aqueous solution with PdNPs@MoS₂ (sample-2), an overpotential of 253 mV was observed. Furthermore, OER performance was highly favorable through rapid reaction kinetics and a low Tafel slope of 59 mV dec⁻¹, as well as high durability and stability. In accordance with the electrochemical results, sample-2 showed also a lower charge transfer resistance, which again provided evidence of OER activity. The enhanced OER activity was attributed to a number of factors, including structural, surface chemical compositions, and synergistic effects between MoS₂ and PdNPs.