Study of the formation of amorphous carbon and rGO-like phases from palmyra sugar by variation of calcination temperature

We have processed biomass from palmyra sugar to produce allotrope carbon by heating process with the variation of calcination temperature. The formation of amorphous carbon (a-C) was confirmed from the XRD result heated at 400°C with the observation of the peak at the position of ~24o. By increasing the temperature at 700°C, the presence of two peaks at 24o and 43o were observed, indicating the formation of rGO-like phase. The functional groups detected by FTIR spectra consist of C=C, C-O, C=O, C-H and O-H. The result of conductivity measurement exhibits that the material can be classified as semiconducting materials

Oxidation state analysis of LiFeSixP1-xO4/C (x = 0.06) with X-ray absorption near edge structure (XANES) in Fe K-edge and Si K-edge

The development of LiFePO4 as a cathode materials on lithium-ion battery was increased with the use of additional techniques such as atomic doping and coating. The material used in this report was LiFeSi0.06P0.94O4/C (LFP Si-6%), synthesized with doping silicon 6% and 11wt% carbon coating by a solid state method. X-ray Absorption Spectroscopy (XAS) characterization was used to investigate the effect on electronic and atomic structure of LFP Si-6%, especially in X-ray Absorption Near Edge Strucuture (XANES) region. XANES data measured on Fe K-edge and Si K-edge. Fe foil, FeO, Fe2O3, FePO4, Si powder, SiO, SiO2 were used as a standard sample for comparison with the result of LFP Si-6%. XANES analysis showed that the energy absorption of Fe K-edge and Si K-edge in LFP Si-6% was 7124.94 eV and 1846.16 eV, respectively. The oxidation state of Fe was Fe2.576+ between Fe2+ and Fe3+, while Si was close to the estimation of Si4+. In addition, the linear combination fitting (LCF) in XANES Fe K-edge was performed to show the ratio of Fe2+/Fe3+ (FeO/Fe2O3)