Influence of hydrothermal carbonization on formation of curved graphite structures obtained from a lignocellulosic precursor

In this letter we report the preparation of curved graphite structures from crude biomass by using hydrothermal carbonization followed by pyrolysis. High resolution transmission electron microscopy (HRTEM) showed clearly the determinant role of the hydrothermal carbonization as an intermediate process, since the highly curved graphite structures were formed only when the crude biomass is pre-treated hydrothermally. X-ray diffraction (XRD) and Raman Spectroscopy techniques confirmed the presence of (0 0 2) graphite planes and sp2 carbon network, thus evidencing a higher organization degree for samples hydrothermally treated prior to the pyrolysis step.