Ultrathin graphene nanosheets derived from rice husks for sustainable supercapacitor electrodes

Lee, Sejoon; Jung, Hyun Suk; Kim, Aran; Ahmed, Abu Talha Aqueel; Inamdar, Akbar I.; Kim, Hyungsang; Lee, Seung Joo; Im, Hyunsik; Kim, Deuk Young

doi:10.1039/c7nj03136j

Cited by 105 publications

(48 citation statements)

References 54 publications

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“…65-6212), while the peak around 44 • relates to the (100) crystal plane of sp 2 -hybridized carbon [35][36][37]. These results demonstrate that the as-prepared HPC possess a graphitic structure [38][39][40]. Figure 2b presents Raman spectroscopy of the HPC material.…”

Section: Electrochemical Measurementsmentioning

confidence: 79%

Hierarchically Porous Carbon Derived from Biomass Reed Flowers as Highly Stable Li-Ion Battery Anode

et al. 2020

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As lithium-ion battery (LIB) anode materials, porous carbons with high specific surface area are highly required because they can well accommodate huge volume expansion/contraction during cycling. In this work, hierarchically porous carbon (HPC) with high specific surface area (~1714.83 m2 g−1) is synthesized from biomass reed flowers. The material presents good cycling stability as an LIB anode, delivering an excellent reversible capacity of 581.2 mAh g−1 after cycling for 100 cycles at a current density of 100 mA g−1, and still remains a reversible capacity of 298.5 mAh g−1 after cycling for 1000 cycles even at 1000 mA g−1. The good electrochemical performance can be ascribed to the high specific surface area of the HPC network, which provides rich and fast paths for electron and ion transfer and provides large contact area and mutual interactions between the electrolyte and active materials. The work proposes a new route for the preparation of low cost carbon-based anodes and may promote the development of other porous carbon materials derived from various biomass carbon sources.

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Section: Electrochemical Measurementsmentioning

confidence: 79%

Hierarchically Porous Carbon Derived from Biomass Reed Flowers as Highly Stable Li-Ion Battery Anode

et al. 2020

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“…Synthesis of SCM is achieved by using the sol-gel method whereas LRGONR is obtainedb yr educing lacey graphene oxide nanoribbons (LGONR) as reported by Sahu et al [26] Sol-gel is as imple, costeffective, low-temperature, and widely explored synthesis route. [29] Thermogravimetric analysis (TGA) was carried out on both the samples ( Figure S1 ba nd FigureS2) in nitrogen and oxygen environments to estimate the oxygen vacancy concentration.T he weight loss percentage of the SCM and SC samples at 900 8Ci sd educed as 3.96 %a nd 1.9 %, respectively.T he oxygen vacancies wered etermined to be 16.36 and 7.7 at. [27,28] The SCM electrode demonstrates an excellents pecific capacitance of 1223.34 Fg À1 at 1Ag À1 in 6 m KOH.…”

Section: Introductionmentioning

confidence: 85%

“…The averagec rystallite size of SCM and SC is estimated to be 25.31 and 27.53 nm, respectively,b yu sing the Scherrer formula. [29] Thermogravimetric analysis (TGA) was carried out on both the samples (Figure S1 ba nd FigureS2) in nitrogen and oxygen environments to estimate the oxygen vacancy concentration.T he weight loss percentage of the SCM and SC samples at 900 8Ci sd educed as 3.96 %a nd 1.9 %, respectively.T he oxygen vacancies wered etermined to be 16.36 and 7.7 at. % for SCM and SC, respectively,e valuated by using previousi nvestigations.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of a Mo‐Doped Strontium Cobaltite Perovskite Hybrid Supercapacitor Cell with High Energy Density and Excellent Cycling Life

2018

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Enriched with oxygen vacancies, Mo-doped strontium cobaltite (SrCo Mo O , SCM) is synthesized as an oxygen anion-intercalated charge-storage material through the sol-gel method. The supplemented oxygen vacancies, good electrical conductivity, and high ion diffusion coefficient bestow the SCM electrode with excellent specific capacitance (1223.34 F g ) and specific capacity (168.88 mAh g ) at 1 A g . The decisive constant (b-value) deduced for the charge storage mechanism (low scan-rate region) is nearly 0.8, indicating a highly capacitive process. In the high scan-rate region, however, the b-value is almost 0.5, and a linear pattern of charge (q) versus the inverse of the square root of the scan rate (v ) is obtained. The results reveal O diffusion as the rate-limiting factor for charge storage. Furthermore, a hybrid cell (SCM∥LRGONR) is fabricated by using lacey, reduced graphene oxide nanoribbon (LRGONR) as the negative electrode, which exhibits a high energy density (74.8 Wh kg at a power density of 734.5 W kg ). With a charging time of only 20.7 s, the cell sustains a very high energy density (33 Wh kg ) with a high power delivery rate (6600 W kg ). The excellent cycling stability (165.1 % activated specific capacitance retention and 97.6 % of the maximum value attained) after 10 000 charge-discharge cycles, demonstrates SCM is a potential electrode material for supercapacitors.

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“…It shows the materials containing random microcrystalline carbon fragments are in amorphous forms, possibly due to the existence of various inorganic compounds and impurities. However, there are two distinct broad peaks at 17.6 o and 28 o in all samples prior to activation, most likely corresponding to the crystallographic planes (100) and semi-crystalline PAN (110) [ 37 , 38 ]. After activation, the spectra exhibit very broad diffraction peaks with the absence of a sharp peak.…”

Section: Resultsmentioning

confidence: 99%

Novel Activated Carbon Nanofibers Composited with Cost-Effective Graphene-Based Materials for Enhanced Adsorption Performance toward Methane

et al. 2020

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Various types of activated carbon nanofibers’ (ACNFs) composites have been extensively studied and reported recently due to their extraordinary properties and applications. This study reports the fabrication and assessments of ACNFs incorporated with graphene-based materials, known as gACNFs, via simple electrospinning and subsequent physical activation process. TGA analysis proved graphene-derived rice husk ashes (GRHA)/ACNFs possess twice the carbon yield and thermally stable properties compared to other samples. Raman spectra, XRD, and FTIR analyses explained the chemical structures in all resultant gACNFs samples. The SEM and EDX results revealed the average fiber diameters of the gACNFs, ranging from 250 to 400 nm, and the successful incorporation of both GRHA and reduced graphene oxide (rGO) into the ACNFs’ structures. The results revealed that ACNFs incorporated with GRHA possesses the highest specific surface area (SSA), of 384 m2/g, with high micropore volume, of 0.1580 cm3/g, which is up to 88% of the total pore volume. The GRHA/ACNF was found to be a better adsorbent for CH4 compared to pristine ACNFs and reduced graphene oxide (rGO/ACNF) as it showed sorption up to 66.40 mmol/g at 25 °C and 12 bar. The sorption capacity of the GRHA/ACNF was impressively higher than earlier reported studies on ACNFs and ACNF composites. Interestingly, the CH4 adsorption of all ACNF samples obeyed the pseudo-second-order kinetic model at low pressure (4 bar), indicating the chemisorption behaviors. However, it obeyed the pseudo-first order at higher pressures (8 and 12 bar), indicating the physisorption behaviors. These results correspond to the textural properties that describe that the high adsorption capacity of CH4 at high pressure is mainly dependent upon the specific surface area (SSA), pore size distribution, and the suitable range of pore size.

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Ultrathin graphene nanosheets derived from rice husks for sustainable supercapacitor electrodes

Abstract: Ultrathin graphene nanosheets were derived from rice husks via KOH activation and they showed excellent electrochemical performances.

Cited by 105 publications

References 54 publications

Hierarchically Porous Carbon Derived from Biomass Reed Flowers as Highly Stable Li-Ion Battery Anode

Hierarchically Porous Carbon Derived from Biomass Reed Flowers as Highly Stable Li-Ion Battery Anode

Fabrication of a Mo‐Doped Strontium Cobaltite Perovskite Hybrid Supercapacitor Cell with High Energy Density and Excellent Cycling Life

Novel Activated Carbon Nanofibers Composited with Cost-Effective Graphene-Based Materials for Enhanced Adsorption Performance toward Methane

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