Ultralight Graphene/Carbon Nanotubes Aerogels with Compressibility and Oil Absorption Properties

Zhao, Da; Yu, Leshu; Li, Dongxu

doi:10.3390/ma11040641

Cited by 24 publications

(7 citation statements)

References 23 publications

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“…Compared with the water contact angle of LGA (∼100°, shown in Figure S4), the improved hydrophobicity of CLGA could be attributed to the simultaneous effect of the enhanced reduction degree and micro/nanorough structure on a aerogel surface, which was consistent with the aforementioned FTIR, XPS, and AFM results on surface chemistry and surface roughness. The density of CLGA was approximately 4.2 mg/cm 3 , not only lower than that of LGA (6.7 mg/cm 3 ) but also significantly lower than that of most of the reported literature. , This ultra-low density of CLGA was consistent with the SEM results on the internal structural network that CLGA possessed more abundant pores with smaller sizes, with the assistance of cysteamine forming more vertical connections between graphene nanosheets. As shown in Figure b, CLGA could stand on the tomentum of setaria viridis without deforming, further confirming its ultra-low density …”

Section: Results and Discussionsupporting

confidence: 86%

Assembly of Ultralight Dual Network Graphene Aerogel with Applications for Selective Oil Absorption

Dai

Sun

et al. 2020

Langmuir

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High-performance graphene aerogels with welldeveloped internal structures are generally obtained by means of introducing additive materials such as carbon nanotubes, cellulose, and lignin into the aerogel network, which not only enhances the cost but also complicates the preparation process. Therefore, tailoring the internal structure of pristine graphene aerogel in a feasible way to achieve high performance is of great significance to the practical applications. Herein, a novel cysteamine/L-ascorbic acid graphene aerogel (CLGA) was fabricated by a simple one-step hydrothermal method followed by freeze-drying. Through the creative combination of the reducing agent L-ascorbic acid and cross-linking agent cysteamine, a dual-network structure was constructed by both layered physical stacking and vertical chemical cross-linking. The addition of cysteamine not only enhanced the reduction degree but also assisted the formation of more vertical connections between graphene nanosheets, resulting in more abundant pores with smaller sizes compared with graphene aerogels prepared by the traditional hydrothermal reduction method. CLGA possessed an ultra-low density of 4.2 mg/cm 3 and a high specific surface area of 397.9 m 2 /g. As expected, this dual-network structure effectively improved the absorption capacity toward a variety of oil and organic solvents, with an outstanding oil absorption capacity up to 310 g/g. Furthermore, CLGA possessed good mechanical properties and oil/water selectivity. The absorbed oil could be recovered by both continuous absorption-removal process and mechanical squeezing, making the as-prepared aerogel superior absorbent material for a variety of applications, such as selective oil absorption and water treatment.

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Section: Results and Discussionsupporting

confidence: 86%

Assembly of Ultralight Dual Network Graphene Aerogel with Applications for Selective Oil Absorption

Dai

Sun

et al. 2020

Langmuir

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“…Graphene-based materials have attracted great attention in nanotechnology because of their amazingly attractive properties, such as high theoretical specific surface area (2630 m 2 g −1 ), superior electron mobility, easy self-assembling into three-dimensional (3D) macroscopic materials with controlled microstructures, high mechanical, chemical, thermal, and electrochemical stabilities, etc. Therefore, graphene-based materials have already been widely applied in many fields, including but not limited to nanoelectronics [ 1 ], energy storage and conversion [ 2 , 3 ], sorption/separation [ 4 ], water purification [ 5 ], sensor [ 6 ], etc. However, pristine graphene suffers from several shortcomings, including a zero bandgap and structural defects chemical inertness.…”

Section: Introductionmentioning

confidence: 99%

Fluorinated Graphene Prepared by Direct Fluorination of N, O-Doped Graphene Aerogel at Different Temperatures for Lithium Primary Batteries

Qiu

et al. 2018

Materials

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Fluorinated graphene (FG) has been a star material as a new derivative of graphene. In this paper, a series of fluorinated graphene materials are prepared by using N, O-doped graphene aerogel as precursor via a direct fluorination method, and the effect of fluorination temperature on the FG structure is investigated. The prepared FG samples are systematically characterized by scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. It is found that the structure of FG, including features such as layer size, chemical composition, chemical bond state of the component elements, etc., is significantly related to the fluorination temperature. With the change of the fluorination temperature, fluorine atoms enter the graphene framework by a substitution process of the N, O-containing groups, including residual phenol, ether, carbonyl groups, or C–N groups, and the addition to CC bonds, subsequently forming a fluoride with different fluorine contents. The fluorine content increases as the fluorination temperature increases from 200 °C to 300 °C, but decreases at a fluorination temperature of 350 °C due to the decomposition of the fluorinated graphene. The prepared FG samples are used as cathode material for lithium primary batteries. The FG sample prepared at 300 °C gives a high specific capacity of 632 mAh g−1 and a discharge plateau of 2.35 V at a current density of 10 mA g−1, corresponding to a high energy density of 1485 Wh kg−1.

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“…Supplementary Figure S3 depicts the hydrogels after freeze-drying process which showed the retainment of the cylindrical monolith reduced graphene hydrogel in the presence of the Mg 2+ and Ca 2+ . The surface of the reduced graphene hydrogel after freeze dry becomes hydrophobic [51,52]. From previously reported studies, the freeze-drying process removed water molecules embedded in the pore structure, which leads to the collapse of the framework due to π-π interactions between the graphene sheets.…”

Section: Characterization Of Go Colloidal Suspension In the Presence mentioning

confidence: 98%

Hydrothermally Reduced Graphene Hydrogel Intercalated with Divalent Ions for Dye Adsorption Studies

et al. 2021

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Fundamental studies involving divalent ion intercalated graphene-based hydrogel are still lacking in terms of their adsorption behavior towards dye pollutants. In this study, we prepared a self-assembled Mg2+ and Ca2+ intercalated reduced graphene hydrogel (rGH) using hydrothermal treatment to evaluate the intercalation impact on the adsorption capability towards cationic dyes, methylene blue and rhodamine B. The morphological, structural, thermal, and textural properties of the divalent ion intercalated reduced graphene hydrogels were studied using Fourier transform infrared spectrometer, thermogravimetric analysis, Raman spectroscopy, scanning electron microscope-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area analysis, and X-ray diffraction. The increased adsorption capacity of the divalent ion intercalated reduced graphene-based hydrogels towards the dye molecules resulted from the increase in the specific surface area and pore volume due to the Mg2+ and Ca2+ bridging that formed spaces between the graphene sheets framework. Adsorption kinetics and the equilibrium adsorption isotherm were fitted by a pseudo-second-order alongside intraparticle diffusion kinetic models and Langmuir isotherm respectively. In addition, the divalent ion intercalated reduced graphene hydrogel showed good generation after three cycles of simultaneous adsorption.

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Ultralight Graphene/Carbon Nanotubes Aerogels with Compressibility and Oil Absorption Properties

Cited by 24 publications

References 23 publications

Assembly of Ultralight Dual Network Graphene Aerogel with Applications for Selective Oil Absorption

Assembly of Ultralight Dual Network Graphene Aerogel with Applications for Selective Oil Absorption

Fluorinated Graphene Prepared by Direct Fluorination of N, O-Doped Graphene Aerogel at Different Temperatures for Lithium Primary Batteries

Hydrothermally Reduced Graphene Hydrogel Intercalated with Divalent Ions for Dye Adsorption Studies

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