N‐doping Hierarchical Porosity Carbon from Biowaste for High‐Rate Supercapacitive Application

Abstract

In this work, nitrogen‐doped carbon materials with hierarchical porosity were prepared from biowaste of soybean curd residue (SCR) by KOH activation. The morphology, structure and textural properties of the carbon materials are investigated by scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, Raman spectroscopy, and N2 absorption‐desorption isotherms, respectively. The products exhibit high specific surface area of 3431 m2 g−1, high nitrogen doping level, outstanding charge storage capacity of 282 F g−1 at the current density of 0.5 A g−1 and good electrochemical stability over 10000 cycles. Moreover, it still retains 200 F g−1 (71 % of its capacitance at 0.5 A g−1) at 20 A g−1. The findings pave the way for improving charge storage capacity of supercapacitors based on activated carbon and provide a new method to transfer biowaste to effective electrode material.

Calcium Chloride Activation of Mung Bean: A Low‐Cost, Green Route to N‐Doped Porous Carbon for Supercapacitors

“…The mung bean carbons with different structures and compositions offer a chance for investigating the structure‐performance relationship of bio‐carbon as supercapacitor. Based on other works, two points are beneficial to the specific capacitance of carbon material: (1) hierarchical nanostructure composed of macroporous and meso/microporous, which facilitates fast mass transport, along with large surface area for electrical charge storage; (2) heteroatom doping generate extra pseudocapacitance As shown in Figure , the specific capacitance was calculated by GCD curves and correlated with BET surface area, N content, charge transfer resistance Rct, and defect degree I D /I G . The results indicate that the specific capacitance correlates positively to the BET surface area, N content, and I D /I G .…”

Efficient Removal of Methylene Blue by Micro-/Mesoporous Heteroatom-doped Biochar Derived from Waste Bovine Horn

“…Recently, biochars derived from biomass have been developed as promising adsorbents for water treatment. Bene ting from the natural structure and composition of biomass, various biomasses, including bamboo [2], leather shavings [3], soybean curd residue [4], coconut shell [5], peanut shells [6], and distillers grains [7], have been utilized to produce biochars with high speci c surface area and abundant active sites, which are generally required to achieve high adsorption performance for pollutants. This strategy not only recycles waste biomass but also produce adsorbents with high adsorption capacity and low economic cost.…”

Sustainable electrodes for the next generation of redox flow batteries

“…The choice of carbon sources from biomaterials has great influence on the properties of the resulting carbon, particularly in terms of heteroatom doping and graphitic carbon content. Unlike PAN, elements different than nitrogen can dope the carbon structure, the most common being nitrogen [19,20], oxygen [21], phosphorus [22,23], and sulphur [24]. Most of the reported electrodes based on the use of biomaterials still involve the use of carbon felts as support, although there have been some recent promising attempts to develop freestanding biomass-derived electrodes for RFBs [25][26][27].…”