Facile synthesis of novel Cu2NiBiX4 (X = Se, S) chalcogenides as bifunctional electrocatalysts for oxygen evolution reaction (OER) and supercapacitive performance

There is a high requirement for very efficient catalytically active materials to produce and store sustainable fuels to fulfill global energy demand, and the design of cost-effective multifunctional electrocatalysts for the oxygen evolution reaction (OER) and supercapacitors has become prominent. Herein, quaternary chalcogenides of Cu2NiBiS4 and Cu2NiBiSe4 have been fabricated by a facile solvothermal method and applied for electrocatalytic OER and supercapacitance performance. Material characterization was undertaken with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), and UV-visible spectroscopy. The Cu2NiBiSe4 catalyst shows a low overpotential of 175 at 10 mA cm−2 current density and a low Tafel slope of 61 mV dec−1 for the OER. Whereas the Cu2NiBiS4 electrocatalyst retains an overpotential of 212 mV and Tafel slope of 78 mV dec−1 for the OER at 10 mA cm−2. A long-term durability test of Cu2NiBiSe4 for 12 h at 10 mA cm−2 current density suggests that it may be a suitable substitute for noble-metal-based electrocatalysts for the oxidation of water in alkaline media. Moreover, Cu2NiBiSe4 delivers boosted supercapacitive behavior with an exceptional specific capacity of 1443 F g−1 at 2.5 A g−1 compared to Cu2NiBiS4 (1221 F g−1 at 2.5 A g−1). Furthermore, Cu2NiBiSe4 exhibits an admirable energy density of 24.3 W h kg−1 at a power density of 450.7 W kg−1 together with 98% retention after 100 cycles.