Cr doped CeO2 nanoparticles as supercapacitor electrodes

The consumption of electrical energy has greatly increased lately, and the requirement of portable charge storage devices has also increased. To fulfill this, a versatile rare earth element CeO2 in nanoparticle form is selected and synthesized through a cost effective precipitation method for supercapacitor application. To improve its efficiency, 2% and 4% of transition metal chromium were doped into the ceria lattice, and their electrochemical properties were studied. The cubic fluorite structure with an average crystallite size of all the samples was 16 nm, which was confirmed through x-ray diffraction analysis. Peculiar rice shaped clusters are observed for 2% Cr doped samples through field emission scanning electron microscopy analysis. The N2 adsorption desorption studies were performed to calculate the surface area of the prepared samples. A maximum specific capacitance of 42.6 F g−1 was obtained for the 2% Cr doped CeO2 sample at 5 mV s−1 in 2M KOH in cyclic voltammetric studies. The galvanostatic charge–discharge and electrochemical impedance spectroscopy measurements were also taken to analyze the charge–discharge cycles and stability of the samples.