Biomass Derived N-Doped Porous Carbon Made from Reed Straw for an Enhanced Supercapacitor

Abstract

Developing advanced carbon materials by utilizing biomass waste has attracted much attention. However, porous carbon electrodes based on the electronic-double-layer-capacitor (EDLC) charge storage mechanism generally presents unsatisfactory capacitance and energy density. Herein, an N-doped carbon material (RSM-0.33-550) was prepared by directly pyrolyzing reed straw and melamine. The micro- and meso-porous structure and the rich active nitrogen functional group offered more ion transfer and faradaic capacitance. X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) measurements were used to characterize the biomass-derived carbon materials. The prepared RSM-0.33-550 possessed an N content of 6.02% and a specific surface area of 547.1 m2 g−1. Compared with the RSM-0-550 without melamine addition, the RSM-0.33-550 possessed a higher content of active nitrogen (pyridinic-N) in the carbon network, thus presenting an increased number of active sites for charge storage. As the anode for supercapacitors (SCs) in 6 M KOH, RSM-0.33-550 exhibited a capacitance of 202.8 F g−1 at a current density of 1 A g−1. At a higher current density of 20 A g−1, it still retained a capacitance of 158 F g−1. Notably, it delivered excellent stability with capacity retention of 96.3% at 20 A g−1 after 5000 cycles. This work not only offers a new electrode material for SCs, but also gives a new insight into rationally utilizing biomass waste for energy storage.

Mild and Efficient One-Step Synthesis of Nitrogen-Doped Multistage Porous Carbon for High-Performance Supercapacitors

“…Figure 4b shows that two drum peaks occurred at 1354 cm −1 and 1590 cm −1 , corresponding to peaks D (disordered peak) and G (graphite peak), respectively. It is generally considered that the ratio of the intensity of the two peaks (I D /I G ) is minor when the graphitization level of the measured carbon material is higher [37]. In this study, the I D /I G values of YAC, N-YAC 0.5 , and N-YAC 1 were 1.13, 1.10, and 1.05, respectively.…”

N,S‐Co‐Doped Activated Carbon Prepared by a Thiourea‐Assisted “Cutting” Method and their Application as High‐Performance Supercapacitors

“…As shown in Figure S6, NSAC consistently demonstrates superior performance among the three products. Additionally, the electrochemical performance of NSAC is found to be competitive with that of other carbon‐based electrodes (Table S1) [50–59] …”

“…Additionally, the electrochemical performance of NSAC is found to be competitive with that of other carbon-based electrodes (Table S1). [50][51][52][53][54][55][56][57][58][59] Electrochemical impedance spectra (EIS) were employed to investigate the ion diffusion properties of the tested samples, and the findings are depicted in the Nyquist plots. As illustrated in Figure 11a, the Nyquist plots consist of a semicircle in the high-frequency range (representing the charge transfer resistance and surface properties of the electrode) and a straight line in the low-frequency range (corresponding to the capacitive behavior of the electrode).…”

The Influence of Oxidation and Nitrogenation on the Physicochemical Properties and Sorption Capacity of Activated Biocarbons Prepared from the Elderberry Inflorescence

“…However, this was not a fully satisfactory result for this activation variant. For example, activated carbons obtained via chemical activation of such precursors as: wheat bran [ 43 ], reed straw [ 44 ], lotus seed pods [ 45 ], acacia wood [ 46 ] or miscanthus and switchgrass [ 47 ] achieved specific surface area and total pore volume at the level of 339–1796 m 2 /g and 0.13–1.52 cm 3 /g, respectively. Therefore, the procedure for the production of activated biocarbons from elderberry inflorescences required further optimisation.…”