Title : Enhancing CeO2 thin films with Mo doping for high performance supercapacitors
Abstract:
This research reports the electrochemical electrodes in energy storage devices of Molybdenum doped cerium oxide (Ce1-xMoxO2) thin films, synthesizes using Spray pyrolysis method. Through the mechanism of oxygen vacancy creation within the CeO2 structure, we improved its electrochemical storage capacity. The Mo doping significantly influenced the physicochemical properties and energy storage performance of films, as revealed by various characterization techniques. XRD and Raman spectroscopy analyzes confirmed a polycrystalline Fluorine-type structure of the synthesized layers, with a reduction in crystallite size observed as the Mo doping concentration increased. The characteristic Raman peak at 461 cm-1, corresponding to the CeO2 lattice, shifted toward lower frequencies due to doping-induced oxygen vacancies. A broad peak, characteristic of oxygen vacancies, was observed in the range of 540-630 cm-1, with its intensity increasing as a result of the substitution of Ce4+ ions by Mo ions. SEM-EDS analysis revealed that the layers exhibited good adhesion, low roughness, and minimal oxygen deficiency. Optical studies indicated that the doped layers had lower transmittance (60–80%) compared to undoped CeO2, with the optical band gap decreasing from 3.28 eV to 2.89 eV at 6%Mo doping. Cyclic voltammetry (CV) results demonstrated that Mo incorporation enhanced the specific capacitance of CeO2 thin films, attributed to increased concentration of Ce3+/Vo sites. The electrode doped with 6% Molybdenum exhibited the highest specific capacitance of 209.16 F. g-1 at 20 mV/s (302.55 F. g-1 at 0.5 A g-1), with only a 2.73% capacitance loss after 1000 cycles.
Keywords: Ce1-xMoxO2 thin films; Doping; Supercapacitor; TEM; CV; oxygen vacancies; storage capacity.
