Authors: | Choi, Daiwon; Jampani, Prashanth H.; Jayakody, J. R. P.; Greenbaum, Steven G.; Kumta, Prashant N. |
Title: | Synthesis, surface chemistry and pseudocapacitance mechanisms of VN nanocrystals derived by a simple two-step halide approach |
Type: | Journal Article |
Publisher: | Materials Science and Engineering: B
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Year: | 2018 |
Volume: | 230 |
Issue: | |
Start Page: | 8-19 |
End Page: | |
DOI: | 10.1016/j.mseb.2017.12.017 |
WEB-link: | http://www.sciencedirect.com/science/article/pii/S092151071730332X |
Abstract: | Chloroamide precursors generated via a simple two-step ammonolysis reaction of transition metal chloride in the liquid phase at room temperature were heat treated in ammonia at moderate temperature to yield nano-sized VN crystallites. Grain growth inhibited by lowering the synthesis temperature (H400/ýC) yielded agglomerated powders of spherical crystallites of cubic phase of VN with particle sizes as small as 6/nm in diameter. X-ray diffraction, FTIR, mass spectroscopy (MS), and nuclear magnetic resonance (NMR) spectroscopy assessed the ammonolysis and nitridation reaction of the VCl4-NH3 system. X-ray Rietveld refinement, the BET technique and high-resolution transmission microscopy (HRTEM), energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA) helped assess the crystallographic and microstructural nature of the VN nanocrystals. The surface chemistry and redox reaction leading to the gravimetric pseudo-capacitance value of (H855/F/g) measured for the VN nanocrystals was determined and validated using FTIR, XPS and cyclic voltammetry analyses.
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Keywords: | Supercapacitors |
File: | (1186K) |