Ternary Copper Tungsten Sulfide (Cu(2)WS(4)) Nanoparticles Obtained through a Solvothermal Approach: A Bi-Functional Electrocatalyst for the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER)

In this work, Cu(2)WS(4) nanoparticles have been synthesized via a solvothermal decomposition approach using a heterobimetallic single source precursor, WCu(2)S(4)(PPh(3))(3). The single source precursor, WCu(2)S(4)(PPh(3))(3), has been characterized using multinuclear NMR spectroscopy, while Cu(2)WS(4) nanoparticles have been characterized by powder X-ray diffraction (PXRD) for which Rietveld refinement has been performed to authenticate the lattice structure of the decomposed product, Cu(2)WS(4). Furthermore, FESEM and EDAX analyses have been performed to assess the morphology and composition of Cu(2)WS(4). An electrochemical study in acidic as well as basic media suggested that Cu(2)WS(4) nanoparticles possess efficient bifunctional activity towards electrochemical hydrogen as well as oxygen evolution reactions. Linear sweep voltammetry (LSV) performed in 0.5 N H(2)SO(4) indicates an onset potential for the HER of 462 mV and a Tafel slope of 140 mV dec(−1). While LSV performed in 0.1 M KOH indicates an onset potential for the OER of 190 mV and a Tafel Slope of 117 mV dec(−1).