Synthesis and Characterization of Carbon Nano/Microspheres from Starch by Low-Temperature Hydrothermal Procedure

A convenient method of synthesis of carbon nano​/microspheres by hydrothermal at very low temp. of 190 °C has been reported. The method uses starch, a polysaccharide material as carbon source in an acidic medium. The product obtained was subjected for characterization after washing and drying. X-​ray powder diffraction, Fourier transform IR and Raman spectroscopic studies reveal the graphitic nature of the products. The SEM and transmission electron microscopic images show the large no. of free spheres. Mostly they are microspheres with some nanospheres having a mean diam. of 100 nm-​1 μm. The surface area and pore vol. values as calcd. are 2.9559 m2/g and 0.006161 cm3/g resp. The spheres display a unimodal pore size distribution. The mechanism of the formation of carbon microspheres under hydrothermal conditions can be ascribed to direct dehydration polymn. and self- assembling fusion process. The scanning electron microscopic images depict a larger amt. of carbon microspheres nearly about 85-​95​% present in the product.