Enhanced UV emission and supercapacitor behavior of Zn doped CeO2 quantum dots

Abstract

The impact of Zn dopant on the phase, energy gap, functional group, microstructure, cyclic voltmeter and GCD behavior of CeO2 quantum dots prepared via a simple precipitation method is discussed in this article. The XRD analysis indicates that Zn doping doesn’t alter the basic FCC structure of CeO2. The crystalline size and lattice constant were found to decrease with increasing the Zn dopant. The optical studies disclose that Zn2+ doping increases the bandgap (Eg) of CeO2 from 3.39 to 3.86 eV. The blue shift in the absorption edge confirmed the quantum confinement effect. The photoluminescence spectra displayed strong UV emission due to Zn doping in CeO2 quantum dots. FESEM and TEM study reveals that the synthesized samples consist of spherical to nanoclusters morphology and the particle size varies between 11 and 4 nm. The presence of Ce-Zn-O bonds has been identified via FT-IR and EDS analysis. The electrochemical analysis suggests that the reported samples exhibit better electrochemical behavior. GCD study confirmed the 5 wt% Zn doped CeO2 quantum dots exhibit a higher specific capacitance of 358Fg−1 at a current density of 10Ag−1. The electrode stability was tested for Zn doped CeO2 electrode it shows 96% of cyclic stability even after 1000 continuous charge-discharge cycles. The cyclic voltmeter, GCD, power density, energy density and cyclic stability analysis suggest that the Zn doped CeO2 quantum dots could be utilized as electrode material for supercapacitor application.