A powerful approach to fabricate nitrogen-doped graphene sheets with high specific surface area

Yang, Shao-Ming; Chang, Kuo‐Hsin; Huang, Yuan-Li; Lee, Ying-Feng; Tien, Hsi-Wen; Li, Shin-Ming; Lee, Ying-Hui; Liu, Chia-Hong; Chen‐Chi, M.; Hu, Chi‐Chang

doi:10.1016/j.elecom.2011.10.028

Cited by 96 publications

(32 citation statements)

References 35 publications

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“…[18] -614 Orange peel [19] CO 2 618 Glucose [20] KOH 1197 Palm date seed [21] NaOH 1282 Desert shrub [22] ZnCl 2 1296 Rice husk [23] H 3 PO 4 1498 Hazelnut shell [24] KOH 1700 Glucose [25] KOH 1704 Sucrose [26] H 3 PO 4 2120 Glucose [26] NaOH 2129 Starch [27] KOH 2190 Rye straw [28] KOH 2200 Eucalyptus sawdust [29] KOH 2252 Corncobs [30] KOH 2300 Hemp bast fiber (this study) KOH 2425 Figure 1 provides the N 2 adsorption-desorption isotherms at −196 • C and pore size distributions of HAC, where HACs were prepared using different biochar-to-KOH ratios at a synthesis temperature of 390 • C. All the adsorption-desorption isotherms exhibit a type IV isotherm with a type IV hysteresis loop (according to IUPAC classification) in the relative pressure range from 0.4 to 1.0. Type IV isotherms are an indication of the existence of well-developed mesopores in the structure, whereas a type IV hysteresis loop indicates the formation of asymmetric, slit-shaped mesopores, attributable to rapid gas evolution and open channels [31]. It has been observed that increasing the ratio of activating agent to biochar increases the textural properties (surface area and pore volume) significantly, attributed to increasing the etching effect of the activating reagent on the biochar surface, thus creating mesopores from micropores [32].…”

Section: Resultsmentioning

confidence: 99%

High-Surface-Area Mesoporous Activated Carbon from Hemp Bast Fiber Using Hydrothermal Processing

Hossain

et al. 2018

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Synthesis of activated carbon from waste biomass is of current interest towards sustainability. The properties of biomass-derived activated carbon largely depend on the carbonization process. This study reports the preparation of mesoporous activated carbon with extremely high surface area from hemp bast fiber using hydrothermal processing. Hot water processing (390-500 • C) followed by activation using KOH and NaOH was investigated at different mass ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp-derived activated carbon (HAC) from activation [confirmed by BJH (Barrett-Joyner-Halenda) pore size distribution and TEM (transmission electron microscopy) imaging]. BET (Brunauer-Emmett-Teller) results showed that the product has an extremely high surface area (2425 m 2 /g) while the surface functional groups (-OH, -COOH, C=C/C-C) were confirmed by FTIR (Fourier transform infrared spectroscopy) and further quantified by XPS (X-ray photoelectron spectroscopy). Increasing KOH concentration was found to enhance the surface area with a maximum biochar-to-KOH (g/g) ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.

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Section: Resultsmentioning

confidence: 99%

High-Surface-Area Mesoporous Activated Carbon from Hemp Bast Fiber Using Hydrothermal Processing

Hossain

et al. 2018

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“…It is generally believed that the KOH activation process of any carbon material enhances the pore structure and morphology with a substantial increase in specific surface area [11]. mesopores in the structure, whereas a type IV hysteresis loop indicates the formation of asymmetric, slit shaped mesopores, attributable to rapid gas evolution and open channels [28].…”

Section: Resultsmentioning

confidence: 99%

High Surface Area Mesoporous Activated Carbon from Hemp Bast Fibre Using Hydrothermal Processing

Hossain¹,

Wu²,

Xu³

et al. 2018

Preprint

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Synthesis of activated carbon from waste biomass is of current interest towards sustainability.The properties of biomass derived activated carbon largely depends on the carbonization process. This study reports preparing extremel high surface area mesoporous activated carbon from hemp bast fibre using hydrothermal processing. Processing in hot water (390-500 o C), then activation using KOH and NaOH was investigated at different loading ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp derived activated carbon (HAC) from activation (confirmed by BJH pore size distribution and TEM imaging). BET results showed that the product has an extremely high surface area (2425 m 2 /g) while the surface functional groups (-OH, COOH, C=C/C-C) were confirmed and quantified by XPS and FTIR results. Increasing KOH concentration was found to enhance the surface area with an optimum biochar to KOH ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.

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“…McAllister et al proposed that fast heating to temperatures above 550°C at ambient pressure yields high rGO surface areas and few-layered solid products, which is achieved through the fast insertion of GO sample into a pre-heated tube furnace. Since then, the process of fast insertion of the GO sample into a pre-heated furnace has been adopted by many other research groups [20, 34–36]. More recently, Yang et al performed a study on the relationship between the thermal reduction parameters - including high vacuum, target decomposition temperature and instrument imposed external heating rate effects (up to 50 K/min) - on the product rGO surface area [24].…”

Section: Introductionmentioning

confidence: 99%

Influence of external heating rate on the structure and porosity of thermally exfoliated graphite oxide

Qiu

Moore

Hurt

et al. 2017

Carbon

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Fast external heating rates in graphite oxide thermal exfoliation have been reported to be advantageous for generating high surface area graphene-based materials for a variety of applications. The study yields the surprising result that the surface area and porosity developed in reduced graphite oxide under some conditions are independent of instrument-set external heating rates. The true “total” heating rate experienced by the sample is shown to be the sum of the external rate and the local self-heating rate associated with the exothermicity of graphite oxide exfoliation, and under many conditions, the local self-heating contribution dominates. In these instances, increasing external heating rate does not increase the total rate, improve exfoliation degree or enhance surface area. These results are important for optimizing the conditions for fabrication of reduced graphene oxide with tailored properties.

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A powerful approach to fabricate nitrogen-doped graphene sheets with high specific surface area

Cited by 96 publications

References 35 publications

High-Surface-Area Mesoporous Activated Carbon from Hemp Bast Fiber Using Hydrothermal Processing

High-Surface-Area Mesoporous Activated Carbon from Hemp Bast Fiber Using Hydrothermal Processing

High Surface Area Mesoporous Activated Carbon from Hemp Bast Fibre Using Hydrothermal Processing

Influence of external heating rate on the structure and porosity of thermally exfoliated graphite oxide

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