Investigation of the supercapacitor behavior of MoS2 and Fe-doped MoS2 nano-flowers synthesized using the hydrothermal method

Abstract

Flower-like nanosheets of pure molybdenum disulfide (MoS₂) and Fe-doped MoS₂ (FM) with 2, 4 and 8% atomic-doped iron of FM-2, FM-4 and FM-8, respectively, were successfully synthesized using the hydrothermal method. The effect of iron doping on the MoS₂ morphology, composition, and supercapacitor behavior are systematically investigated. In the Fe-doped MoS₂ samples, iron atoms replaced the molybdenum atoms in the MoS₂ structure through the hydrothermal process. Cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements were conducted on a three-electrode system to evaluate the electrochemical performance of the electrodes. The specific capacitance of the FM-2 electrode was 240 F g⁻¹ at a 10 mV s⁻¹ CV scan rate, which was higher than that of the pure MoS₂ and the other two Fe-doped MoS₂ electrodes. Furthermore, EIS tests exhibited that doping iron in the MoS₂ structure contributes to a rapid decline in charge transfer resistance and, therefore, a higher probability of energy storage. The results revealed that the synthesized Fe-doped MoS₂ samples are potential electrode materials for future energy storage devices.