rGO supported CuMoO4 nanoparticles: synthesis, characterization, and electrocatalytic oxygen evolution reaction

Abstract

Several well-known electrocatalysts, including RuO₂ and IrO₂, have been used extensively for oxygen evolution reactions (OERs) in alkaline medium. However, the main issues with the application of these electrocatalysts in OER are their high cost and scarcity. Therefore, the search for low-cost and equally efficient OER electrocatalyst materials is still under progress. This study focuses on the synthesis of low-cost electrocatalysts, i.e. reduced graphene oxide (rGO) supported CuMoO₄ nanoparticles (CuMoO₄ NPs@rGO nanocomposites), for electrochemical water splitting reactions particularly OER. The prepared materials were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) studies. The electrochemical water splitting reactions were investigated in an alkaline medium (i.e. 0.5 M KOH) at room temperature for OER. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurements reveal that the CuMoO₄@rGO nanocomposite electrocatalysts show superior OER activity than pure CuMoO₄ nanoparticles. Furthermore, the lower Tafel slope of CuMoO₄@rGO nanocomposites (∼250 mV dec⁻¹) than CuMoO₄ nanoparticles (∼415 mV dec⁻¹) confirmed the higher OER performance of the nanocomposites.