Hydrothermal synthesis of spherical carbon nanoparticles (CNPs) for supercapacitor electrodes uses

In this paper, hydrothermal method was used to provide stable colloidal suspension of spherical carbon nanoparticles (CNPs) with good uniformity of size and shape. XRD analyses showed the formation of crystalline structure of carbon material. CNPs Raman spectrum indicates the high quality with a low content of structural defects and high graphitic degree. The formation of CNPs is confirmed by an absorption peak at 264 nm. XPS technique showed well a significant decrease of oxygen-containing functional groups, indicating a low degree of graphite oxidation. The active surface area of CNPs was measured by BET technique. TEM images show that CNPs are nearly spherical in shape and the diameters varying between 50 and 120 nm. The CV behaviors showed that CNPs exhibit the higher specific capacitance values, and is greatly improved over that of previously reported carbon nanomaterials.