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 (RCT) and series resistance (RS) 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.