Design and fabrication of NiFe2O4/few-layers WS2 composite for supercapacitor electrode material

Few-layers WS₂ was obtained through unique chemical liquid exfoliation of commercial WS₂. Results showed that after the exfoliation process, the thickness of WS₂ reduced significantly. Moreover, the NiFe₂O₄ nanosheets/WS₂ composite was successfully synthesized through a facile hydrothermal method at 180 °C, and then proven by the analyses of field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The composite showed a high specific surface area of 86.89 m²·g⁻¹ with an average pore size of 3.13 nm. Besides, in the three-electrode electrochemical test, this composite exhibited a high specific capacitance of 878.04 F·g⁻¹ at a current density of 1 A·g⁻¹, while in the two-electrode system, the energy density of the composite could reach 25.47 Wh·kg⁻¹ at the power density of 70 W·kg⁻¹ and maintained 13.42 Wh·kg⁻¹ at the higher power density of 7000 W·kg⁻¹. All the excellent electrochemical performances demonstrate that the NiFe₂O₄ nanosheets/WS₂ composite is an excellent candidate for supercapacitor applications.