Introduction Phenolic oils (PO) are low-value coal-derived liquids obtained from the distillation... more Introduction Phenolic oils (PO) are low-value coal-derived liquids obtained from the distillation of coal tar. As they are rich in phenol, PO are a priori very interesting precursors for preparing low-cost carbon gels based on sol-gel phenol-formaldehyde polymerization routes. Synthesis of carbon gels from PO and their application as electrode materials for supercapacitors would constitute an important step towards the valorization of those liquids. However, the main difficulty to overcome is that PO has a multi-component nature, with many aromatic compounds and heterocycles of different reactivity. In this study, we synthesized porous carbon gels obtained by sol-gel polymerization of PO (∼ 25 wt.% of phenol) with formaldehyde, using different solvents in either acidic or basic media. The porous texture of the carbons was further developed by KOH activation, and the resultant activated carbons were tested as supercapacitor electrodes. The physicochemical properties of the carbon mat...
Particle & Particle Systems Characterization, 2019
Herein, the development of a novel composite particle system prepared from superparamagnetic Fe3O... more Herein, the development of a novel composite particle system prepared from superparamagnetic Fe3O4@SiO2 microparticles as core and coated with a carbon shell is presented. The coating with carbon is done by pyrolyzing furan resin, which was previously deposited on the particle surface by poly‐merization of furfuryl alcohol. The novel composite material thus combines magnetic and sorptive properties. Upon pyrolysis the magnetic material is converted from magnetite to α‐iron and fayalite, changing its behavior from superparamagnetic to ferromagnetic with nearly zero remanence. The magnetic properties can be utilized to magnetically collect the particles dispersed in fluids, whereas the sorptive properties of the carbon shell can be used to remove organic contaminants from these fluids. The adsorption behavior of the composite particles and a potential electrochemical regeneration route are investigated, using the model dye methylene blue.
Water-assisted mechanosynthesis allows preparing perfectly ordered mesoporous carbons from tannin... more Water-assisted mechanosynthesis allows preparing perfectly ordered mesoporous carbons from tannins without crosslinkers or any drying or curing step.
Environmental science and pollution research international, Jan 31, 2017
The main purpose of this study was to understand the effect of time and temperature during the hy... more The main purpose of this study was to understand the effect of time and temperature during the hydrothermal carbonisation (HTC) of olive stones (OS). For that purpose, the severity factor was introduced, by which the effect of the HTC conditions on the resultant products could be described. HTC was carried out at various temperatures (160, 180, 200, 220 and 240 °C) and times (3, 6, 12, 24 and 48 h) for producing 25 hydrochars. The yield to hydrochar varied from 70 to 50%. Hydrochars were all submitted to thermogravimetric and elemental analysis. The liquid fractions were also recovered and analysed in order to valorise OS as completely as possible. Thus, highly added-value products such as furfural and 5-hydroxymethylfurfural were detected. At the highest temperature and time, the hydrochar elemental composition was similar to that of lignite coals. Hydrochars were further carbonised at 900 °C, leading to materials with surface areas as high as 1200 m(2) g(-1) and with narrow pore s...
The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of por... more The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of porous glassy carbon spheres were experimentally and theoretically investigated in the Ka-band (26–37 GHz) frequency range. The electromagnetic response of such a “moth-eye”-like all-carbon metasurface at a normal incidence angle was modelled on the basis of long-wave approximation. Modelling parameters in the Ka-band were used to estimate and predict the absorption properties of monolayers in free space in the range 1–40 GHz. Experimental and theoretical results demonstrate that a metasurface based on porous glassy carbon spheres is an inert, lightweight, compact, and perfectly absorbing material for designing new effective microwave absorbers in various practically used frequency ranges.
N- and O-doped carbons obtained from water-extracted pine tannins exhibited high performance when... more N- and O-doped carbons obtained from water-extracted pine tannins exhibited high performance when applied as electrodes for supercapacitors.
Herein, the formation of hollow microballoons derived from superparamagnetic iron oxide nanoparti... more Herein, the formation of hollow microballoons derived from superparamagnetic iron oxide nanoparticles with silica patches is reported. Depending on the experimental conditions, single- or multishelled superparamagnetic microballoons as well as multivesicular structures were obtained. We show how such structural changes follow a lifelike process that is based on self-directing Pickering emulsions. We further demonstrate that the key toward the formation of such complex architectures is the patchy nature of the nanoparticles. Interestingly, no well-defined ordering of patches on the particles surface is required, unlike what theorists formerly predicted. The resultant hollow microballoons may be turned into hollow carbonaceous magnetic microspheres by simple pyrolysis. This opens the way to additional potential applications for such ultralightweight (density: 0.16 g·cm(-3)) materials.
Carbons from cane molasses with 8 m2 g−1 BET area yielded capacitances up to 153 F g−1 at 0.5 mV ... more Carbons from cane molasses with 8 m2 g−1 BET area yielded capacitances up to 153 F g−1 at 0.5 mV s−1 in 1 M H2SO4, with 35.2% pseudocapacitance contribution, due to the high surface concentration of quinone and carbonyl groups.
Introduction Phenolic oils (PO) are low-value coal-derived liquids obtained from the distillation... more Introduction Phenolic oils (PO) are low-value coal-derived liquids obtained from the distillation of coal tar. As they are rich in phenol, PO are a priori very interesting precursors for preparing low-cost carbon gels based on sol-gel phenol-formaldehyde polymerization routes. Synthesis of carbon gels from PO and their application as electrode materials for supercapacitors would constitute an important step towards the valorization of those liquids. However, the main difficulty to overcome is that PO has a multi-component nature, with many aromatic compounds and heterocycles of different reactivity. In this study, we synthesized porous carbon gels obtained by sol-gel polymerization of PO (∼ 25 wt.% of phenol) with formaldehyde, using different solvents in either acidic or basic media. The porous texture of the carbons was further developed by KOH activation, and the resultant activated carbons were tested as supercapacitor electrodes. The physicochemical properties of the carbon mat...
Particle & Particle Systems Characterization, 2019
Herein, the development of a novel composite particle system prepared from superparamagnetic Fe3O... more Herein, the development of a novel composite particle system prepared from superparamagnetic Fe3O4@SiO2 microparticles as core and coated with a carbon shell is presented. The coating with carbon is done by pyrolyzing furan resin, which was previously deposited on the particle surface by poly‐merization of furfuryl alcohol. The novel composite material thus combines magnetic and sorptive properties. Upon pyrolysis the magnetic material is converted from magnetite to α‐iron and fayalite, changing its behavior from superparamagnetic to ferromagnetic with nearly zero remanence. The magnetic properties can be utilized to magnetically collect the particles dispersed in fluids, whereas the sorptive properties of the carbon shell can be used to remove organic contaminants from these fluids. The adsorption behavior of the composite particles and a potential electrochemical regeneration route are investigated, using the model dye methylene blue.
Water-assisted mechanosynthesis allows preparing perfectly ordered mesoporous carbons from tannin... more Water-assisted mechanosynthesis allows preparing perfectly ordered mesoporous carbons from tannins without crosslinkers or any drying or curing step.
Environmental science and pollution research international, Jan 31, 2017
The main purpose of this study was to understand the effect of time and temperature during the hy... more The main purpose of this study was to understand the effect of time and temperature during the hydrothermal carbonisation (HTC) of olive stones (OS). For that purpose, the severity factor was introduced, by which the effect of the HTC conditions on the resultant products could be described. HTC was carried out at various temperatures (160, 180, 200, 220 and 240 °C) and times (3, 6, 12, 24 and 48 h) for producing 25 hydrochars. The yield to hydrochar varied from 70 to 50%. Hydrochars were all submitted to thermogravimetric and elemental analysis. The liquid fractions were also recovered and analysed in order to valorise OS as completely as possible. Thus, highly added-value products such as furfural and 5-hydroxymethylfurfural were detected. At the highest temperature and time, the hydrochar elemental composition was similar to that of lignite coals. Hydrochars were further carbonised at 900 °C, leading to materials with surface areas as high as 1200 m(2) g(-1) and with narrow pore s...
The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of por... more The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of porous glassy carbon spheres were experimentally and theoretically investigated in the Ka-band (26–37 GHz) frequency range. The electromagnetic response of such a “moth-eye”-like all-carbon metasurface at a normal incidence angle was modelled on the basis of long-wave approximation. Modelling parameters in the Ka-band were used to estimate and predict the absorption properties of monolayers in free space in the range 1–40 GHz. Experimental and theoretical results demonstrate that a metasurface based on porous glassy carbon spheres is an inert, lightweight, compact, and perfectly absorbing material for designing new effective microwave absorbers in various practically used frequency ranges.
N- and O-doped carbons obtained from water-extracted pine tannins exhibited high performance when... more N- and O-doped carbons obtained from water-extracted pine tannins exhibited high performance when applied as electrodes for supercapacitors.
Herein, the formation of hollow microballoons derived from superparamagnetic iron oxide nanoparti... more Herein, the formation of hollow microballoons derived from superparamagnetic iron oxide nanoparticles with silica patches is reported. Depending on the experimental conditions, single- or multishelled superparamagnetic microballoons as well as multivesicular structures were obtained. We show how such structural changes follow a lifelike process that is based on self-directing Pickering emulsions. We further demonstrate that the key toward the formation of such complex architectures is the patchy nature of the nanoparticles. Interestingly, no well-defined ordering of patches on the particles surface is required, unlike what theorists formerly predicted. The resultant hollow microballoons may be turned into hollow carbonaceous magnetic microspheres by simple pyrolysis. This opens the way to additional potential applications for such ultralightweight (density: 0.16 g·cm(-3)) materials.
Carbons from cane molasses with 8 m2 g−1 BET area yielded capacitances up to 153 F g−1 at 0.5 mV ... more Carbons from cane molasses with 8 m2 g−1 BET area yielded capacitances up to 153 F g−1 at 0.5 mV s−1 in 1 M H2SO4, with 35.2% pseudocapacitance contribution, due to the high surface concentration of quinone and carbonyl groups.
Uploads
Papers by ANGELA SANCHEZ