This paper reports on several mechanisms of carbon aging in a hybrid lithium-ion capacitor operating with 1 mol L LiPF in an ethylene carbonate/dimethyl carbonate 1:1 vol/vol electrolyte. Carbon electrodes were subjected to a constant polarization protocol (i.e.
View Article and Find Full Text PDFThe development of hard carbon (HC) electrodes using biobased binders, formulated in water solvent, is of great interest for Na-ion batteries. Five Na-carboxymethyl cellulose (CMC) binders with different molecular weights and degrees of substitution were investigated. The increase in the CMC molecular weight led to an increase in the volume of water necessary for slurry preparation and a decrease in the electrode mass loading.
View Article and Find Full Text PDFPorous binder-free carbon electrodes were obtained by impregnating cellulose filter papers with phenolic resin through soft-salt template synthesis and thermal pyrolysis. These self-standing electrodes were used directly in a supercapacitor device. To understand the impacts of filter paper (FP) thickness on carbon filter paper (CFP) morphology, porosity, and surface functionalities, five different materials were examined.
View Article and Find Full Text PDFThe physical and chemical characteristics of an adsorbent are key factors determining its efficiency in relation to a particular adsorbate molecule. The adsorption of cyanuric acid (cya) on activated carbon (AC) has not been extensively explored in terms of its basic phenomenon and specific surface interactions. Cya is an important molecule in the swimming pool industry, as it protects free chlorine from UV light degradation.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2023
Potassium vanadium oxyfluoride phosphate of composition KVPOFO was modified by a carbon coating to enhance its electrochemical performance. Two distinct methods were used, first, chemical vapor deposition (CVD) using acetylene gas as a carbon precursor and second, an aqueous route using an abundant, cheap, and green precursor (chitosan) followed by a pyrolysis step. The formation of a 5 to 7 nm-thick carbon coating was confirmed by transmission electron microscopy and it was found to be more homogeneous in the case of CVD using acetylene gas.
View Article and Find Full Text PDFVarious alkali metal (Li, Na, K, Rb, and Cs) chlorides with Pluronic F127 were used as a soft-salt template for tuning the textural and structural properties of carbon. Highly conductive metal hydroxide solutions, where the cations are the same as those in the salt template, have been used as electrolytes. By increasing the size of the cation in the template, the textural properties of carbon, such as the specific surface area, micropore volume, and pore size, were remarkably enhanced.
View Article and Find Full Text PDFThe olive oil industry is an important economic sector in Mediterranean countries. However, oil production is unfortunately accompanied by the generation of huge amounts of olive mill solid wastes (OMSW) and olive mill wastewater (OMWW). In the present study, a strategy is proposed for converting these olive mill wastes into biochar through pyrolysis, for their later use as an organic amendment in agriculture.
View Article and Find Full Text PDFThe reduction of nitroarenes is the most efficient route for the preparation of aromatic primary amines. These reductions are generally performed in the presence of heterogeneous transition metal catalysts, which are rather efficient but long and tedious to prepare. In addition, they contain very expensive metals that are in most cases difficult to reuse.
View Article and Find Full Text PDFHydrothermal carbonization (HTC) is considered as a promising technique for wastes conversion into carbon rich materials for various energetic, environmental and agricultural applications. In this work, the HTC of olive mill wastewater (OMWW) was investigated at different temperatures (180-220 °C) and both, the solid (i.e.
View Article and Find Full Text PDFLatex templating using core-shell particles represents a unique opportunity to design mesoporous carbons with a high level of control on textural properties. This new class of organic colloid templates is synthesized by polymerization-induced self-assembly (PISA) in which a solvophilic poly(hydroxyethyl acrylate) (PHEA) homopolymer is chain extended with a solvophobic polystyrene (PS) via a photomediated reversible-addition-fragmentation-transfer (RAFT) polymerization. The resultant PHEA--PS diblock copolymer nanoparticles exhibit a PS core stabilized by a PHEA shell, with two blocks characterized by a low molecular weight dispersity (1.
View Article and Find Full Text PDFTransition metal hexacyanoferrate/microporous activated carbon composites were obtained using a simple successive impregnation approach. The effect of metal type (nickel, indium, or copper), and the carbon oxidation on the composite characteristics (porosity, metal structure, and particle size), as well as on the removal efficiency of cesium from aqueous solution was investigated. Successful formation of the desired metal hexacyanoferrate phase was achieved and the size of the metallic nanoparticles and their dispersion in the carbon network was found to depend on the metal type, with the indium and nickel-based materials exhibiting the smallest particle size distribution (< 10 nm).
View Article and Find Full Text PDFWe report herein Pd Co nanoalloys confined in mesoporous carbons (Pd -Co @MC) prepared by an eco-friendly one-pot approach consisting in the co-assembly of readily available and non-toxic carbon precursors (phloroglucinol, glyoxal) with a porogen template (pluronic F-127) and metallic salts (HPdCl and Co(NO)·6HO) followed by thermal annealing. Three Pd Co @MC materials with different alloy compositions were prepared (C1: / = 90/10; C2: / = 75/25; C3 and C4: / = 50/50). The nanoalloys were uniformly distributed in the carbon framework and the particle sizes depended on the alloy composition.
View Article and Find Full Text PDFPd-Au nanoalloys confined in mesoporous carbonaceous materials were synthesized by a rapid one-pot microwave assisted approach. Green polymer resins based on phloroglucinol/glyoxylic acid or glyoxal were co-assembled in the presence of a template and metallic salts followed by microwave treatment between 40 and 80°C and subsequent thermal annealing, allowing simultaneous formation of mesoporous carbonaceous materials with in-situ confined Pd-Au nanoparticles. Several Pd-Au compositions were prepared (PdAu, where x=90; 80; 70 and 50) and their impact on the alloy structure and particle size/distribution evaluated.
View Article and Find Full Text PDFRecycling cotton waste derived from the textile industry was used as a low-cost precursor for the elaboration of an activated carbon (AC) through carbonization and zinc chloride chemical activation. The AC morphological, textural, and surface chemistry properties were determined using different analytical techniques including Fourier transform infrared, temperature programmed desorption-mass spectroscopy, nitrogen manometry and scanning electron microscopy. The results show that the AC was with a hollow fiber structure in an apparent diameter of about 6.
View Article and Find Full Text PDFThe design of mesoporous carbon materials with controlled textural and structural features by rapid, cost-effective and eco-friendly means is highly demanded for many fields of applications. We report herein on the fast and tailored synthesis of mesoporous carbon by UV and IR laser assisted irradiations of a solution consisting of green phenolic resins and surfactant agent. By tailoring the UV laser parameters such as energy, pulse repetition rate or exposure time carbon materials with different pore size, architecture and wall thickness were obtained.
View Article and Find Full Text PDFIn-depth clarification of hydrogen interaction with noble metal nanoparticles and nanoalloys is essential for further development and design of efficient catalysts and hydrogen storage nanomaterials. This issue becomes even more challenging for nanoalloys of bulk-immiscible metals. The hydrogen interaction with bulk-immiscible Pd-Rh nanoalloys (3-6 nm) supported on mesoporous carbon is studied by both laboratory and large scale facility techniques.
View Article and Find Full Text PDFDespite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales.
View Article and Find Full Text PDFPd90Co10 and Pd75Co25 nanoalloys embedded into mesoporous carbon hosts have been prepared by two synthetic methods: direct and indirect. The average nanoparticles size can be tuned by both the temperature during thermal treatment and the chemical composition: the higher the treatment temperature and the richer the Pd composition, the larger the nanoparticle size. Twofold size- and composition-dependence of the hydrogen sorption properties at room temperature are evidenced.
View Article and Find Full Text PDFA novel one-pot laser-assisted approach is reported herein for the synthesis of ordered carbons with embedded cobalt nanoparticles. The process is based on a UV pulsed laser exposure of an ethanolic solution consisting of green carbon precursors, a structure directing agent and a cobalt salt. Very short irradiation times (5 to 30 min) are only required to polymerize and cross-link carbon precursors (i.
View Article and Find Full Text PDFThe functionalization of carbon nanomaterials in controlled and selective manner and in order to stabilize small metal nanoparticles is of high interest particularly in the catalysis field. We present the μ-waves assisted few layer graphene (FLG) oxidation in water, which results in a partial sheets exfoliation and formation of oxygen functionalized carbon nanoballs, supported on highly graphitized graphene sheets. This double morphology material allows homogenous anchoring of Pt nanoparticles, while the advantages of planar and highly crystallized FLG are preserved.
View Article and Find Full Text PDFIn this study we attempt to investigate the potential use of two zeolite template carbon (ZTC), EMT-ZTC and FAU-ZTC, to capture CO(2) at room temperature. We report their high pressure CO(2) adsorption isotherms (273 K) that show for FAU-ZTC the highest carbon capture capacity among published carbonaceous materials and competitive data with the best organic and inorganic adsorbing frameworks ever-known (zeolites and mesoporous silicas, COFs and MOFs). The importance of these results is discussed in light of mitigation of CO(2) emissions.
View Article and Find Full Text PDFThe objective of this work was to study the adsorption of different oxygenated hydrocarbons (methanol, ethanol, 1 and 2-butanol, methyl acetate) on activated carbons from organic mixtures with cyclohexane. Three activated carbons prepared by thermal and chemical treatments of a commercial carbon were employed for this purpose. Their textural properties were found to be similar, whereas their surface chemistries were modified, as shown by temperature-programmed desorption coupled to mass spectrometry (TPD-MS) and X-ray photoelectron spectroscopy (XPS).
View Article and Find Full Text PDFSemiconductor metal oxide films of copper-doped tin oxide (Cu-SnO(2)), tungsten oxide (WO(3)) and indium oxide (In(2)O(3)) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities.
View Article and Find Full Text PDF