Ndiaye, Ndeye MatyMasikhwa, T.M. (Tshifhiwa)Ngom, B.D.Madito, M.J. (Moshawe)Oyedotun, Kabir OyeniranDangbegnon, Julien K.Manyala, Ncholu I.2018-06-212018-08Ndiaye, N.M., Masikhwa, T.M., Madito, M.J. et al. 2018, 'Effect of growth time on solvothermal synthesis of vanadium dioxide for electrochemical supercapacitor application', Materials Chemistry and Physics, vol. 214, pp. 192-200.0254-058410.1016/j.matchemphys.2018.04.087http://hdl.handle.net/2263/65205In this work, we report the time-dependent morphological evolution of the as-prepared vanadium dioxide (VO2) and its electrochemical performance for supercapacitor applications. VO2 with different morphologies (microspheres and nanosheets) were successfully synthesised by solvothermal method for time growth ranging from 2 h 30min to 12 h at a temperature of 200 °C. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), gas adsorption/desorption analysis and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure, morphology, composition and the oxidation state of the as-prepared samples. The electrochemical behaviour of the as-prepared VO2 samples were analysed in a three-electrode cell configuration using 6 M KOH aqueous electrolyte. The VO2 samples revealed monoclinic crystal structure (with VO2 (B) monoclinic phase for the samples prepared for 4 h and 6 h and VO2 (A) monoclinic phase for the samples grown for 2 h 30min and 12 h). The VO2 samples grown for 4 h and 6 h displayed nanoflakes and nanosheets-like morphology, respectively, whereas VO2 samples grown for 2 h 30min and 12 h revealed nanorods-like morphology. The 6 h grown sample also showed more porous structure leading to much higher specific surface area, pore volume and enhanced electrochemical performance with highest specific discharge capacity of 49.28 mA h g−1 at current density of 0.5 A g−1 and the corresponding specific capacitance of 663 F g−1 at a scan rate of 5 mV s−1 with excellent cycling stability as compared to others samples. Accordingly, the 6 h is considered to be optimal growth time for VO2 nanosheets for considerable potential as an electrode material for supercapacitor applications.en© 2018 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Materials Chemistry and Physics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Materials Chemistry and Physics, vol. 214, pp. 192-200, 2018. doi : 10.1016/j.matchemphys.2018.04.087.Vanadium dioxide (VO2)Supercapacitors (SCs)X-ray diffraction (XRD)Raman spectroscopyScanning electron microscopy (SEM)High resolution transmission electron microscopy (HRTEM)Energy dispersive spectroscopy (EDS)Gas adsorption/desorption analysisX-ray photoelectron spectroscopy (XPS)Energy storageSolvothermalNanosheetsOstwald-ripening processSpecific discharge capacityMonoclinic crystal structureElectrochemical supercapacitorsElectrochemical performanceElectrochemical behaviourPotassium hydroxideNanorodsMorphologyEnergy storageElectrolytesElectrochemical electrodesElectric dischargesCrystal structurePostprint Article