Saccharum spontaneum, a precursor of sustainable activated carbon: Synthesis, characterization and optimization of process parameters and its suitability for supercapacitor applications

摘要

In the present study, microporous activated carbon with high surface area is prepared from a wasteland weed i.e. Saccharum spontaneum by chemical activation with ZnCl2. Input parameters are varied at different impregnation (ZnCl2/sample) ratios (0.5-1) and carbonization temperatures (400-600 degrees C). Under continuous N-2 flow of about 100 ml/min with holding time for (10-60 min), carbonization is carried out. The activated samples are analyzed in terms of surface area, pore-volume, micro and mesopore volume by nitrogen adsorption-desorption isotherms. Identification of process parameters, that is statistically significant, is done using ANOVA. To determine the optimal activation conditions up to a useful level of accuracy, signal to noise ratio and ANOVA analysis is applied. The surface area obtained within the range of 304.08-1205.71 m(2)/g, achieving maximum pore volume up-to 0.943 cm(3)/g. Under the varied parameters, as per the design of experiment (DOE), using Taguchi analysis, optimal condition for control factors to produce high surface area, are 600 degrees C, 60 min, and 1 chemical ratio. Saccharum spontaneum has been proved to be a precursor for activated carbon with a microporous structure. It is found from this study that, the impregnation ratio and carbonization temperature are the most effective parameters, among all others, those affect the surface area and yield%, respectively. Surface morphology of all the samples has been characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), Raman Spectroscopy, Scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM). The appropriateness of activated samples is analyzed and could prove that the synthesized samples are suitable for energy storage applications.