Structural, morphological, electrochemical, and supercapacitance capability of NiCoMoO4-doped MoS2 nanoplates

Abstract

In this study, spinel-nanostructured NiCoMoO₄ (NCMO) was synthesized using a hydrothermal method and subsequently doped on molybdenum disulfide plates through the same process. The synthesized compounds were characterized using different instrumental methods. Spinel-nanostructured NCMO exhibited a regular shape and a flower-like morphology with a monoclinic crystal phase and an average 452 nm crystallite size. The NCMO@MoS₂ nanocomposite showed the same morphology with 236 nm crystallites. The thermal gravimetry analysis showed that this compound has good thermal stability, losing only 41.70% of its weight up to 600 °C. Also, the use of the NCMO@MoS₂ nanocomposite as an asymmetric supercapacitor was investigated. The results showed that at a current density of 50 mA g⁻¹, the NCMO@MoS₂ electrode achieved a maximum capacitance of 571.42 F g⁻¹, along with a power density of 1785.5 W kg⁻¹ and an energy density of 83.19 Wh kg⁻¹, demonstrating its effective functioning as a supercapacitor. Also, the obtained charge transfer resistance (R_CT) and series resistance (R_S) from electrochemical impedance spectroscopy were 1.40 Ω and 1.02 Ω, respectively. These characteristics confirm the ideal supercapacitor behavior. In addition, the NCMO@MoS₂ electrode showed good cyclic stability after 2000 cycles and maintained 88% of its initial capacity. An NCMO@MoS₂//AC asymmetric supercapacitor was created for practical use and showed a capacitance of 75 mF g⁻¹, along with a power density of 900 W kg⁻¹ and an energy density of 0.015 Wh kg⁻¹ at a current density of 9 mA g⁻¹.