NiCuCoS3 chalcogenide as an efficient electrocatalyst for hydrogen and oxygen evolution

Abstract

Herein, a newly developed non-noble metal water splitting catalyst based on NiCuCoS3 was reported. Water splitting catalysts are largely developed with noble-based transition metals to lower the energy requirement for the overall water splitting reactions. However, the high cost of precious metal-based catalyst necessitated ongoing search for cheap and efficient oxygen and hydrogen evolution reaction catalysts. NiCuCoS3 were prepared by solventless solid state method and was well characterized by several techniques including field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared red spectroscopy (FTIR), energy dispersive X-ray spectroscopy (XEDS). The as-prepared NiCuCoS3 was applied for water splitting activities with satisfactory performance. The onset for the oxygen evolution reaction (OER) in 1 M KOH was noticed at the electrode potential E = 1.78 V/RHE (vs. the reversible hydrogen electrode corresponding to an overpotential η = 0.55 V, with a current density of 10 mA cm−2 obtained at E = 1.92 V/RHE (η = 0.69 V). Similarly, the hydrogen evolution reaction (HER) occurred at an onset of E = −0.58 V/RHE, with a current density of 10 mA/cm2 obtained at E = 0.60 V/RHE (with η equal to E vs. RHE for the HER). Likewise, OER and HER had Tafel slopes (130 mV/dec and −116 mV/dec respectively). The developed catalyst also showed high stability as established by linear sweep voltammetry, chronoamperometry and chronopotentiometry. This approach is seen as the right track of making water electrolysis for hydrogen energy feasible through provision of low-energy requirement for electrolytic process.