Preparation of activated biomass carbon from pine sawdust for supercapacitor and CO ₂ capture

Abstract

Summary Biomass based carbon has captured more and more attention because it is environmentally friendly and has properties of low cost and ideal sustainability. In this study, three kinds of activated biomass carbons (ie, ABC‐700, ABC‐800 and ABC‐900) were first carbonized through pine sawdust pyrolysis and then activated using KOH under three different activation temperatures (ie, 700°C, 800°C and 900°C). The structure properties of the prepared activated biomass carbons were characterized by N2‐adsorption/desorption, SEM, TEM, XRD, Raman, XPS, TG and ultimate analysis. To clarify the activation mechanism, the gas products produced during KOH activation process were measured online with an ETG gas analyzer. The performance of the activated biomass carbons derived from pine sawdust for supercapacitor and CO2 capture was then evaluated. The predominant gas products during the activation process are H2 and CO. It indicates that the porous structure was created by using an enhanced etching reaction between carbon atoms and KOH. An increment of the activation temperature from 700 to 900°C results in the increase of surface area (from 1728.66 to 2330.89 m2/g) and total pore volume (from 0.671 to 1.914 cm3/g). Among the three samples, ABC‐900 exhibits the maximal specific capacitance of 175.6 F·g−1 and high energy density of 24.39 Wh·kg−1 at the 0.5 A·g−1. And the ABC‐700 shows the maximal CO2 capture capacity of 4.21 mmol/g and high selectivity of CO2 over N2 at 298 K and 1 bar. In addition, ABC‐700 also has excellent stability and reproducibility after 15 times adsorption‐desorption cycles. The unexceptionable electrochemical performance and adsorption capacity of the biomass‐carbons show its broad application prospects in the field of supercapacitors and CO2 capture.

Porous bamboo‐like CNTs prepared by a simple and low‐cost steam activation for supercapacitors

“…[13][14][15] For example, pine sawdust-derived ACs prepared by the pyrolysis and subsequent chemical activation with KOH offered a specific capacity of 176 F g −1 at 0.5 A g −1 . 16 Chestnut shell-derived ACs synthesized by a mild activating agent K 2 SO 4 reached a specific capacity of 216 F g −1 at 0.2 A g −1 . 17 Chitin-based ACs prepared by CuCl 2 Á2H 2 O as theactivator exhibited a specific capacity of 227 F g −1 at 0.5 A g −1 and a retention of 67.7% even at 50 A g −1 .…”

One-step production of N–O–P–S co-doped porous carbon from bean worms for supercapacitors with high performance

“…38 For BWPCs, the (002) peaks become broader and weaker, which might be due to the KOH activation destroys the atomic arrangement, corresponding to the porosity change from nonporous structure to porous structure. 39,40 Raman spectra of BWC and BWPCs were studied for more structural information. As shown in Fig.…”

Highly porous honeycomb‐like activated carbon derived using cellulose pulp for symmetric supercapacitors

“…Due to low cost, low generation of energy, and environmentally friendliness, these materials can be significant to reduce the dependency on high‐cost precursors 11,12 . Deriving activated carbon from the solid waste can be a solution to the combating global waste disposal issues 13,14 …”