Abstract
Nanocrystalline-graphite produced from pyrolyzed vegetable oil has properties that deviate from typical graphites, but is similar to the previously reported Graphite/Graphene from the University of Idaho Thermolyzed Asphalt Reaction (GUITAR). GUITAR has the classical basal and edge plane morphology similar to graphite and graphene with similar X-ray photoelectron spectroscopy (XPS), Raman and IR characteristics. However, GUITAR is electrochemically different from both graphite and graphene. GUITAR has (i) faster heterogeneous electron transfer rate across its basal plane, (ii) an electrochemical window that exceeds graphitic materials by 1 V and (iii) higher corrosion resistance beyond graphitic materials. To discover the structural basis for these properties, characterization of GUITAR was investigated with Raman and X-ray photoelectron spectroscopies, density, X-ray diffraction (XRD), thermogravimetric and elemental analyses (see Chapter-1). These characteristics established GUITAR as a new form of carbon different from previous forms. The aforementioned beneficial electrochemical properties of GUITAR are examined for application in different fields like as electrochemical energy storage (vanadium redox flow battery – VRFB, chapter-2) and electrochemical sensing of important electroactive analytes (chemical oxygen demand – COD and free chlorine – HOCl and ClO-, see chapter 3 and 4, respectively). The results explained in this dissertation show that GUITAR is an excellent alternative material for the negative electrode in the vanadium redox flow battery and an effective sensor material for determination of chemical oxygen demand and free chlorine.