Preparation and characterization studies of La doped CuS nanospheres by microwave irradiation for high performance supercapacitors

Highlights: • Biopolymer encapsulated CuS and La doped CuS NPs synthesized by chemical reflux method. • La doped CuS NPs were analysed by XRD, FTIR, SEM, TEM and EDX techniques. • La doped CuS NPs were investigated electrochemical studies (CV, GCD and ESI) with 1 M of KOH aqueous electrolyte solution. • Cyclic life of 91% retention of capacitance after 1000 cycles was found. -- Abstract: Lanthanum (Rare earth metal) doped CuS (La@CuS) at different compositions (0%, 1%, 3% and 5% of La) are synthesized by encapsulation of sodium alginate biopolymer using microwave irradiation method. The prepared various compositions of La@CuS are examined by structural characterizations, particle size and identifications of elements from XRD, TEM and EDX spectrum. The surface morphological studies are conformed by SEM and TEM images. Optical properties and characteristics peak are confirmed with UV, FTIR and Raman spectroscopic tools. In addition to that the electrochemical performances are studied using Cyclic Voltammetry (CV), Galvanostatic charge and discharge (GCD) and electrochemical impedance spectroscopy (EIS) investigations. The specific capacitance is found to be 1329 F/g for 5% of La doped CuS nano spheres.