Tailoring cobalt doped zinc oxide nanocrystals with high capacitance activity: factors affecting structure and surface morphology

By Davis, Marauo; Gumeci, Cenk; Black, Bria; Korzeniewski, Carol & Hope-Weeks, Louisa
Published in RSC Adv. The Royal Society of Chemistry 2012

Abstract

Highly crystalline zinc cobaltite (ZnCo2O4) nanocrystals were successfully synthesized through an epoxide driven, sol-gel method using Zn(NO3)[middle dot]6H2O and CoCl2[middle dot]6H2O as precursors. The crystal phase, morphology, specific surface areas, porosity, and capacitance activity of the prepared materials were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), gas sorption techniques, and cyclic voltammetry, respectively. Results reveal that the synthesized nanocrystals are [similar]4 nm in diameter. Electron microscopy studies illustrate significant changes brought on by varying the solvent and epoxide. Gas sorption analyses detail high specific surface areas (>200 m2 g-1) and porosities of the as prepared and annealed samples. Cyclic voltammetry experiments show that these zinc cobaltite nanocrystals have exceptional capacitance ([similar]700 Fg-1) and excellent cycle durability making them an excellent electrode material for supercapacitors.

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