Publication details

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  
Year: 2018 
Volume: 230 
Start Page: 8-19 
End Page:  
DOI: 10.1016/j.mseb.2017.12.017 
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.  
Keywords: Supercapacitors 
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