Surface and porous characterization of activated carbon prepared from pyrolysis of biomass (rice straw) by two-stage procedure and its applications in supercapacitor electrodes

Abstract

In this study, we used a two-stage process and phosphoric acid to thermochemically transform waste biomass rice straw into porous carbon (PC) for the preparation of high-performance supercapacitor electrodes. The morphological and chemical characteristics of PC were investigated by X-ray diffraction, scanning electron microscopy, surface area, and porosity analyses by the BET (Brunauer, Emmett, and Teller) nitrogen adsorption method, Fourier transform infrared spectroscopy. The modification process leads to the increase in the specific surface area and pore size of PC. The dc conductivity of the samples determined at room temperature was found to increase from 16.1 9 10 -5 to 10.16 9 10 -3 X -1 cm -1 . The samples showed good electrochemical property with specific capacitance possessing in the range of 56-112 F/g. It was found that the carbonization temperature plays a crucial role on the evolution of structural and electrochemical properties of porous carbons. These porous carbons which show a particular large reversible capacity are proved to be promising electrode materials for high-rate and high-performance supercapacitors.

Self-Biotemplate Preparation of Hierarchical Porous Carbon with Rational Mesopore Ratio and High Oxygen Content for an Ultrahigh Energy-Density Supercapacitor

“…Up to now, several works have been reported on preparing porous carbons from RS. 24,25 Unfortunately, none of them utilized the intrinsic silica as a self-biotemplate to develop N-self-doped HPCs. And thus, the supercapacitances and rate capacities or energy densities of the as-prepared porous carbons are moderate.…”

Monolith solid porous carbon approach derived from Garcinia Xanthochymus for high-performance electrode material of supercapacitor

“…This indicates that the highest sample density reduction was found at GX-via activation of 35.86% confirming the high porosity nature which is dominated by various pore structures. This property is very much needed for the basic electrode material as a supercapacitor energy storage application [34]. From the density analysis of this monolith, it can be confirmed that the sample GXvia activation produces good material properties to improve their electrochemical properties in supercapacitor applications [35].…”

An ultrasonic-assisted synthesis of rice-straw-based porous carbon with high performance symmetric supercapacitors

“…At present, the main preparation methods of biomass-activated carbon include direct heating carbonization, hydrothermal carbonization and carbonization-activation. [25][26][27] The biomass-activated carbon prepared by direct thermal carbonization or hydrothermal carbonization has small specic surface area, small pore diameter and low capacitance, which are not suitable for the preparation of high-performance electrode materials for double-layer supercapacitors. However, the carbonization activation method of pre-carbonization and subsequent activation by adding an activator can effectively solve the problems.…”