Supercapacitive Behavior of Two Glucose-Derived Microporous Carbons: Direct Pyrolysis versus Hydrothermal Carbonization

This is the accepted version of the following article: Sevilla, M., Yu, L., Ania, C. O. and Titirici, M.-M. (2014), Supercapacitive Behavior of Two Glucose-Derived Microporous Carbons: Direct Pyrolysis versus Hydrothermal Carbonization. CHEMELECTROCHEM, 1: 2138–2145. doi: 10.1002/celc.201402233, which has been published in final form at http://dx.doi.org/10.1002/celc.201402233. This article may be used for non-commercial purposes in accordance with the Wiley Self-Archiving PolicyThe physical and chemical characteristics of activated carbons produced from glucose and hydrothermally carbonized glucose are compared for the first time, as well as their performance as electrodes in supercapacitors with aqueous electrolyte (H2SO4). Both KOH-activated carbons exhibit similar textural properties, with Brunauer–Emmett–Teller surface areas of ≈1400–1500 m2 g−1 and a pore volume of ≈0.70 cm3 g−1, with the pore size distribution centered in the micropore range. When tested as supercapacitor electrodes, the activated carbon produced from hydrothermally carbonized glucose exhibits a superior rate capability, owing to lower equivalent distributed resistance (being able to work at an ultrahigh discharge current of 90 A g−1), as well as higher specific capacitance (≈240 F g−1 vs. ≈220 F g−1 for the glucose-derived activated carbon at 0.1 A g−1). Both supercapacitors have excellent robustness, even for a large cell voltage of 1.2 V in 1 M H2SO4.This research work was supported by Spanish MINECO (MAT2012-31651 and CTM2011-23378). M.S. acknowledges the award of the Ramón y Cajal contract. M.M. Titirici and Linghui Yu are grateful to the Max-Planck Society for financial support for this project.Peer reviewe

Surface Modification of CNTs with N-Doped Carbon: An Effective Way of Enhancing Their Performance in Supercapacitors

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry and Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher.To access the final edited and published work see http://dx.doi.org/10.1021/sc500069hCarbon nanotubes have been successfully coated with a N-doped carbon layer via hydrothermal carbonization in the presence of a nitrogen-containing carbohydrate, i.e., glucosamine hydrochloride. By controlling the amount of glucosamine added, it was possible to tune the N content of the composites N-doped carbon/CNT between 1.8–2.5 wt %. The prepared composites exhibited superior supercapacitor performance in comparison to bare CNTs even though they possess lower textural properties. Thus, a 2- to 4-fold increase in specific capacitance per surface area was registered at low current densities and sweep rates and a 2-fold increase in energy density, while keeping the power density. Besides, the composites possess superb long-term stability, losing only 4–6% of specific capacitance after 10,000 cycles at 10 A g–1.This research work was supported by Spanish MINECO (MAT2012-31651 and CTM2011- 23378). M.S. acknowledges the award of the Ramón y Cajal contract.Peer reviewe

Iron-catalyzed cascade synthesis of nitrogen polycycles from alkynoic acids and functionalized amines

Catalysis by first-row transition metals is of increasing interest in the context of the scarcity of chemical resources. For instance, iron is promising due to its abundance, low toxicity and unique electronic features. Here we synthesized quinazoline alkaloids from alkynoic acids and functionalized amines in the presence of iron dibromide and pyridine in toluene or, alternatively, in a solventless reaction system. We studied iron sources, reaction media and the effect of additives. Results show 39-99% yields and regioselective preparation of nitrogen- and oxygen-containing scaffolds. This is the first example of a cascade process involving alkynoic acids catalyzed by iron. Fe is more abundant, cheaper and less toxic than other Au, Cu and Ru catalysts previously reported for similar transformations.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by the Basque Government (IT1405-19) and the Spanish Ministry of Economy and Competitiveness (CTQ2017-86630-P). JD thanks the Basque Government for a predoctoral scholarship. Finally, technical and human support provided by SGIker of UPV/EHU is gratefully acknowledged

Biomass-derived three-dimensional porous N-doped carbonaceous aerogel for efficient supercapacitor electrodes

Functionalized carbonaceous materials with hierarchical structure and developed porosity are highly desired in energy storage and conversion fields. In this work, a facile and scalable hydrothermal methodology was established to synthesise three-dimensional (3D) N-doped carbonaceous aerogels using biomass-based starting materials and polypyrrole as N-source. The effect of different calcination temperatures on the structural properties, type and content of N-species and electrochemical performance of the 3D N-doped carbonaceous aerogels were uncovered. Thanks to the combinatorial effect of the appropriate N content and porous structure, the obtained samples exhibited excellent electrochemical performance, in particular, an outstanding specific capacitance of 281.0 F g-1 achieved on the sample calcined at 600 °C. This methodology offers a new fabrication strategy to prepare nanoscale carbonaceous materials with desirable morphology and hierarchical architecture of great potentials for the applications in energy fields

Surface Modification of CNTs with N-Doped Carbon: An Effective Way of Enhancing Their Performance in Supercapacitors

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Evaluación de la aplicación del mix-marketing por parte del sector de Hospedería Mayor del Municipio de León en el período compredido de febrero-agosto del año 2009

Tesis (Lic. en Mercadotecnia)-Universidad Nacional Autónoma de Nicaragua, LeónEvaluación de la aplicación del Mix-marketing por parte del sector de hospedería mayor del municipio de León en el período de Febrero – Agosto del año 2009.UNAN-Leó

Surface Modification of CNTs with N‑Doped Carbon: An Effective Way of Enhancing Their Performance in Supercapacitors

Carbon nanotubes have been successfully coated with a N-doped carbon layer via hydrothermal carbonization in the presence of a nitrogen-containing carbohydrate, i.e., glucosamine hydrochloride. By controlling the amount of glucosamine added, it was possible to tune the N content of the composites N-doped carbon/CNT between 1.8–2.5 wt %. The prepared composites exhibited superior supercapacitor performance in comparison to bare CNTs even though they possess lower textural properties. Thus, a 2- to 4-fold increase in specific capacitance per surface area was registered at low current densities and sweep rates and a 2-fold increase in energy density, while keeping the power density. Besides, the composites possess superb long-term stability, losing only 4–6% of specific capacitance after 10,000 cycles at 10 A g^–1