Highly improved supercapacitance properties of MnFe(2)O(4) nanoparticles by MoS(2) nanosheets

Manganese ferrite (MnFe(2)O(4)) nanoparticles were synthesized via a hydrothermal method and combined with exfoliated MoS(2) nanosheets, and the nanocomposite was studied as a supercapacitor. X-ray diffractometry and Raman spectroscopy confirmed the crystalline structures and structural characteristics of the nanocomposite. Transmission electron microscopy images showed the uniform size distribution of MnFe(2)O(4) nanoparticles (~ 13 nm) on few-layer MoS(2) nanosheets. UV–visible absorption photospectrometry indicated a decrease in the bandgap of MnFe(2)O(4) by MoS(2), resulting in a higher conductivity that is suitable for capacitance. Electrochemical tests showed that the incorporation of MoS(2) nanosheets largely increased the specific capacitance of MnFe(2)O(4) from 600 to 2093 F/g (with the corresponding energy density and power density of 46.51 Wh/kg and 213.64 W/kg, respectively) at 1 A/g, and led to better charge–discharge cycling stability. We also demonstrated a real-world application of the MnFe(2)O(4)/MoS(2) nanocomposite in a two-cell asymmetric supercapacitor setup. A density functional theory study was also performed on the MnFe(2)O(4)/MoS(2) interface to analyze how a MoS(2) monolayer can enhance the electronic properties of MnFe(2)O(4) towards a higher specific capacitance.