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Research Interests: Chemical Engineering, Materials Science, Electrochemistry, Raman Spectroscopy, Carbon Nanotubes, and 12 moreCarbon Nanotube, Optical Spectroscopy, Nanotechnology, Cyclic Voltammetry, Medicine, Semiconductor, Titanium dioxide, Electroquímica, Nanotubos de carbono, Supercapacitor, THEORETICAL AND COMPUTATIONAL CHEMISTRY, and Electrode
Explosive percolation is an experimentally-elusive phenomenon where network connectivity coincides with onset of an additional modification of the system; materials with correlated localisation of percolating particles and emergent... more
Explosive percolation is an experimentally-elusive phenomenon where network connectivity coincides with onset of an additional modification of the system; materials with correlated localisation of percolating particles and emergent conductive paths can realise sharp transitions and high conductivities characteristic of the explosively-grown network. Nanocomposites present a structurally- and chemically-varied playground to realise explosive percolation in practically-applicable systems but this is yet to be exploited by design. Herein, we demonstrate composites of graphene oxide and synthetic polymer latex which form segregated networks, leading to low percolation threshold and localisation of conductive pathways. In situ reduction of the graphene oxide at temperatures of <150 °C drives chemical modification of the polymer matrix to produce species with phenolic groups, which are known crosslinking agents. This leads to conductivities exceeding those of dense-packed networks of r...
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Correction for ‘Optical properties and carrier dynamics in Co-doped ZnO nanorods’ by Aswathi K. Sivan et al., Nanoscale Adv., 2021, DOI: 10.1039/d0na00693a.
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Manuela Cano, Ana M. Benito, Esteban P. Urriolabeitia, Raul Arenal, and Wolfgang K. Maser * Instituto de Carboquímica ICB-CSIC, C/Miguel Luesma Castán, E-50018 Zaragoza, Spain. Fax: +34 976 73 33 18; Tel: +34 976 73 39 77; E-mail:... more
Manuela Cano, Ana M. Benito, Esteban P. Urriolabeitia, Raul Arenal, and Wolfgang K. Maser * Instituto de Carboquímica ICB-CSIC, C/Miguel Luesma Castán, E-50018 Zaragoza, Spain. Fax: +34 976 73 33 18; Tel: +34 976 73 39 77; E-mail: wmaser@icb.csic.es Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Univ. Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain. LMA-INA, Univ. Zaragoza, C/Mariano Esquillor, E-50018 Zaragoza, Spain Fundacion ARAID, C/María de Luna 11, E-50018 Zaragoza, Spain
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Carbon nanotubes (CNTs), graphene aerogels (GAs), and their hybrid (CNT-GA) prepared by hydrothermal treatment were tested in the electrocatalytic oxygen reduction reaction (ORR). The importance of porous structure derived from the... more
Carbon nanotubes (CNTs), graphene aerogels (GAs), and their hybrid (CNT-GA) prepared by hydrothermal treatment were tested in the electrocatalytic oxygen reduction reaction (ORR). The importance of porous structure derived from the combination of mesoporosity coming from CNTs with macroporosity stemming from GAs was evidenced because the hybrid carbon material exhibited synergistic performance in terms of kinetic current and onset potential. Different electrocatalysts were prepared based on these hybrids doped with nitrogen using different precursors and also supporting Fe nanoparticles. N-doped carbon hybrids showed higher electrocatalytic activity than their undoped counterparts. Nevertheless, both doped and undoped materials provided a mixed two and four electron reduction. On the other hand, the addition of a Fe precursor and phenanthroline to the CNT-GA allowed preparing an N-doped hybrid containing Fe nanoparticles which favored the 4-electron oxygen reduction to water, thus b...
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Optoelectronic and photoelectrochemical characterization of Co-doped ZnO nanorods revealing the crucial role of surface defects for enhanced photoresponse.
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In the vast field of conductive inks, graphene-based nanomaterials, including chemical derivatives such as graphene oxide as well as carbon nanotubes, offer important advantages as per their excellent physical properties. However, inks... more
In the vast field of conductive inks, graphene-based nanomaterials, including chemical derivatives such as graphene oxide as well as carbon nanotubes, offer important advantages as per their excellent physical properties. However, inks filled with carbon nanostructures are usually based on toxic and contaminating organic solvents or surfactants, posing serious health and environmental risks. Water is the most desirable medium for any envisioned application, thus, in this context, nanocellulose, an emerging nanomaterial, enables the dispersion of carbon nanomaterials in aqueous media within a sustainable and environmentally friendly scenario. In this work, we present the development of water-based inks made of a ternary system (graphene oxide, carbon nanotubes and nanocellulose) employing an autoclave method. Upon controlling the experimental variables, low-viscosity inks, high-viscosity pastes or self-standing hydrogels can be obtained in a tailored way. The resulting inks and paste...
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Carbon nanotubes (CNTs) processed into conductive films by liquid phase deposition technologies reveal increasing interest as electrode components in electrochemical device platforms for sensing and energy storage applications. In this... more
Carbon nanotubes (CNTs) processed into conductive films by liquid phase deposition technologies reveal increasing interest as electrode components in electrochemical device platforms for sensing and energy storage applications. In this work we show that the addition of acrylic latex to water-based CNT inks not only favors the fabrication of stable and robust flexible electrodes on plastic substrates but, moreover, sensitively enables the control of their electrical and electrochemical transport properties. Importantly, within a given concentration range, the acrylic additive in the films, being used as working electrodes, effectively blocks undesired faradaic transfer reactions across the electrode–electrolyte interface while maintaining their capacitance response as probed in a three-electrode electrochemical device configuration. Our results suggest a valuable strategy to enhance the chemical stability of CNT film electrodes and to suppress non-specific parasitic electrochemical r...
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KPFM reveals the critical role of the aggregate structure in P3HT for achieving efficient phototransport properties in P3HT-GO ensembles.
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The transfer of nanoscale properties from single‐walled carbon nanotubes (SWCNTs) to macroscopic systems is a topic of intense research. In particular, inorganic composites of SWCNTs and metal oxide semiconductors are being investigated... more
The transfer of nanoscale properties from single‐walled carbon nanotubes (SWCNTs) to macroscopic systems is a topic of intense research. In particular, inorganic composites of SWCNTs and metal oxide semiconductors are being investigated for applications in electronics, energy devices, photocatalysis, and electroanalysis. In this work, a commercial SWCNT material is separated into fractions containing different conformations. The liquid fractions show clear variations in their optical absorbance spectra, indicating differences in the metallic/semiconducting character and the diameter of the SWCNTs. Also, changes in the surface chemistry and the electrical resistance are evidenced in SWCNT solid films. The starting SWCNT sample and the fractions as well are used to prepare hybrid electrodes with titanium dioxide (SWCNT/TiO2). Raman spectroscopy reflects the optoelectronic properties of SWCNTs in the SWCNT/TiO2 electrodes, while the electrochemical behavior is studied by cyclic voltamm...
Research Interests: Chemical Engineering, Materials Science, Electrochemistry, Raman Spectroscopy, Carbon Nanotubes, and 12 moreCarbon Nanotube, Optical Spectroscopy, Nanotechnology, Cyclic Voltammetry, Medicine, Semiconductor, Titanium dioxide, Electroquímica, Nanotubos de carbono, Supercapacitor, THEORETICAL AND COMPUTATIONAL CHEMISTRY, and Electrode
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The emission of a bright blue fluorescence is a unique feature common to the vast variety of polymer carbon dots (CDs) prepared from carboxylic acid and amine precursors. However, the difficulty to assign a precise chemical structure to... more
The emission of a bright blue fluorescence is a unique feature common to the vast variety of polymer carbon dots (CDs) prepared from carboxylic acid and amine precursors. However, the difficulty to assign a precise chemical structure to this class of CDs yet hampers the comprehension of their underlying luminescence principle. In this work, we show that highly blue fluorescent model types of CDs can be prepared from citric acid and ethylenediamine through low temperature synthesis routes. Facilitating controlled polycondensation processes, the CDs reveal sizes of 1-1.5 nm formed by a compact network of short polyamide chains of about 10 monomer units. Density functional theory calculations of these model CDs uncover the existence of a spatially separated highest occupied molecular orbital and a lowest unoccupied molecular orbital located at the amide and carboxylic groups, respectively. Photoinduced charge transfer between these groups thus constitutes the origin of the strong blue ...
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The sorption of 4He by graphene oxide powders thermally reduced at T = 200, 300, 500, 700, 900 °C has been investigated in the interval 1.5–290 K. The measured dependence of the quantity of sorbed helium upon the reduction temperature... more
The sorption of 4He by graphene oxide powders thermally reduced at T = 200, 300, 500, 700, 900 °C has been investigated in the interval 1.5–290 K. The measured dependence of the quantity of sorbed helium upon the reduction temperature shows up as a nonmonotonic curve. The highest quantities of helium were sorbed by the samples reduced at T = 300 and 900 °C. It is assumed that the thermal reduction of graphite oxide by heating it to 300 °C causes evaporation of the water intercalated in the spacings of the carbon layers, this results in exfoliation of the graphene planes, which enhances the sorptive capacity. Heating the samples to 900 °C generates numerous defects in the carbon planes, as a result, the interlayer spacings become accessible for sorption, which enhances the sorptive capacity.
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Resumen del trabajo presentado como poster al "International meeting on the chemistry of nanotubes and graphen" celebrado en Francia del 1 al 5 del 2012.
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Multiwalled carbon nanotubes (MWNTs) were incorporated into SiO2 matrices for the first time by means of partial matrix melting caused by a Nd:YAG laser. Due to the rapid very short heating cycle of the laser MWNTs were detected being... more
Multiwalled carbon nanotubes (MWNTs) were incorporated into SiO2 matrices for the first time by means of partial matrix melting caused by a Nd:YAG laser. Due to the rapid very short heating cycle of the laser MWNTs were detected being well incorporated in the silica matrix although temperatures well above 1200ºC are reached. It was found that mainly the ability of
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... WA, Bacsa WS, Chatelain A, Gerfin T, Humphreybaker R, Forro L and Ugarte D 1995 Science 268 8457 [10] Martel R, Schmidt T, Shea HR, Hertel ... and Beyers R 1993 Nature 363 6057 [17] Thess A et al 1996 Science 273 4837 [18] Maser... more
... WA, Bacsa WS, Chatelain A, Gerfin T, Humphreybaker R, Forro L and Ugarte D 1995 Science 268 8457 [10] Martel R, Schmidt T, Shea HR, Hertel ... and Beyers R 1993 Nature 363 6057 [17] Thess A et al 1996 Science 273 4837 [18] Maser WK, Munoz E, Benito AM, Martinez ...
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Sorption and the subsequent desorption of 4He, H2, Ne, N2, CH4, and Kr gas impurities by graphene oxide (GO), glucose-reduced GO (RGO-Gl) and hydrazine-reduced GO (RGO–Hz) powders have been investigated in the temperature interval... more
Sorption and the subsequent desorption of 4He, H2, Ne, N2, CH4, and Kr gas impurities by graphene oxide (GO), glucose-reduced GO (RGO-Gl) and hydrazine-reduced GO (RGO–Hz) powders have been investigated in the temperature interval 2–290 K. It has been found that the sorptive capacity of the reduced sample RGO–Hz is three to six times higher than that of GO. The reduction of GO with glucose has only a slight effect on its sorptive properties. The temperature dependences of the diffusion coefficients of the GO, RGO-Gl, and RGO-Hz samples have been obtained using the measured characteristic times of sorption. It is assumed that the temperature dependences of the diffusion coefficients are determined by the competition of the thermally activated and tunneling mechanisms, the tunneling contribution being dominant at low temperatures.
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Page 1. KOH-Treated Single-Walled Carbon Nanotubes as Electrodes for Supercapacitors A Ansóna, F Picób, JM Rojob, MA Callejasa, AM Benitoa, WK Masera, MT Martíneza. aInstituto de Carboquímica (CSIC). Miguel Luesma Castán 4, 50018... more
Page 1. KOH-Treated Single-Walled Carbon Nanotubes as Electrodes for Supercapacitors A Ansóna, F Picób, JM Rojob, MA Callejasa, AM Benitoa, WK Masera, MT Martíneza. aInstituto de Carboquímica (CSIC). Miguel Luesma Castán 4, 50018 Zaragoza, Spain. ...
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В інтервалі температур 9-290 К досліджена сорбція і подальша десорбція водню порошком оксиду графену, який було термічно відновлено при температурах 200, 300, 500, 700 і 900 °С. Отримана залежність кількості сорбованого водню від... more
В інтервалі температур 9-290 К досліджена сорбція і подальша десорбція водню порошком оксиду графену, який було термічно відновлено при температурах 200, 300, 500, 700 і 900 °С. Отримана залежність кількості сорбованого водню від температури відновлення мала немонотонний характер. Максимальні значення кількості сорбованого водню спостерігалися для зразків, які були відновлені при 300 і 900 °С. Зроблено припущення, що збільшення сорбційної здатності відновленого при 300 °С зразку пояснюється розупорядкуванням шаруватої структури оксиду графену при видаленні інтеркальованої води. Термічна обробка при температурі 900 °С також збільшила сорбційну ємність зразка за рахунок утворення множинних дефектів вуглецевих поверхонь при видаленні кисневмісних груп.В интервале температур 9-290 К исследована сорбция и последующая десорбция водорода порошками оксида графена, термически восстановленного при температурах 200, 300, 500, 700 и 900 °С. Полученная зависимость количества сорбированного водорода от температуры восстановления имела немонотонный характер. Максимальные значения количества сорбированного водорода наблюдались для образцов, восстановленных при 300 и 900 °С. Сделано предположение, что увеличение сорбционной способности образцов, восстановленных при 300 °С, объясняется разупорядочением слоистой структуры оксида графена при удалении интеркалированной воды. Термическая обработка при температуре 900 °С также увеличила сорбционную емкость образца за счет образования множественных дефектов углеродных поверхностей при удалении кислородосодержащих групп.Sorption and subsequent desorption of hydrogen by graphene oxide powder which was thermally reduced at temperatures of 200, 300, 500, 700 and 900 °С were investigated in 9-290 K temperature interval. The resulting dependence of the quantity of adsorbed hydrogen on the reduction temperature had a nonmonotonic character. The maximum values of the quantity of sorbed hydrogen were observed for the samples reduced at temperatures of 300 and 900 °С. It was assumed that the increase in the sorption ability of the samples reduced at 300 °C is due to the disordering of the layered structure of graphene oxide by removing the intercalated water. Heat treatment at 900 °C also increased the sorption capacity of the sample due to the formation of multiple defects of carbon surfaces by removing oxygen-containing groups
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Resumen del poster presentado a la NanoteC16: Carbon Nanoscience and Nanotechnology Conference, celebrada en Dublin (Irlanda) del 31 de agosto al 3 de septiembre de 2016.
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Single-walled carbonnanotube (SWNT)networks weretested asgassensors fornitrogen dioxide detection. Sensor filmswerefabricated by airbrushing SWNT dispersions on alumina substrates. Sensors werecharacterized byresistance measurements... more
Single-walled carbonnanotube (SWNT)networks weretested asgassensors fornitrogen dioxide detection. Sensor filmswerefabricated by airbrushing SWNT dispersions on alumina substrates. Sensors werecharacterized byresistance measurements from25to200°C. Thebestresponse toNO2was obtained at200°C. Thetested SWNT sensors weresensitive to lowNO2 concentrations innitrogen and airatmospheres. Moreover, thesesensors provided noresponse tointerfering gases suchasH2,NH3,toluene andoctane. Theeffect ofthermal treatments onthesensor response wasalsoinvestigated. IndexTerms-carbon nanotubes, gassensor, NO2
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Nanomaterials offer exciting properties and functionalities. However, their production and processing frequently involve complex methods, cumbersome equipments, harsh conditions and hazardous media. The capability of living beings to... more
Nanomaterials offer exciting properties and functionalities. However, their production and processing frequently involve complex methods, cumbersome equipments, harsh conditions and hazardous media. The capability of living beings to accomplish this purpose using mild conditions offers a sustainable, biocompatible and environmentally friendly alternative. Different nanomaterials such as metallic nanoparticles, quantum dots, silica nanostructures or nanocellulose are increasingly being synthesized through living entities. Even more, the bionanofabrication potential enables also the in situ processing of nanomaterials inside biomatrices with unprecedented outcomes. The focus of this Minireview is to present a critical state-of-the-art vision of current nanofabrication approaches mediated by living entities (ranging from unicellular to higher organisms), in order to expand this knowledge and scrutinize future prospects. An efficient interfacial interaction at the nanoscale by green means is at reach through this approach.
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The effect of doping on the electronic properties in bulk single-walled carbon nanotube (SWCNT) samples is studied for the first time using a new in situ Raman spectroelectrochemical method, and further verified by DFT calculations and... more
The effect of doping on the electronic properties in bulk single-walled carbon nanotube (SWCNT) samples is studied for the first time using a new in situ Raman spectroelectrochemical method, and further verified by DFT calculations and photoresponse.
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Research Interests: Chemical Engineering, Physiology, Biophysics, Materials Science, Plant Biology, and 15 morePhotophysics, Interaction, Ecology, Infectious Diseases, Photoelectrochemistry, Medicine, Functionalization, Electron, Polythiophene, Mos, Donor, Solution, Electrostatic Interactions, Optoelectronic, and Photoelectrochemical
Exfoliated semiconducting MoS and WS were covalently functionalized with 1,2-dithiolane-modified carbon nanodots (CNDs). The newly synthesized CND-MoS and CND-WS hybrids were characterized by spectroscopic, thermal, and electron... more
Exfoliated semiconducting MoS and WS were covalently functionalized with 1,2-dithiolane-modified carbon nanodots (CNDs). The newly synthesized CND-MoS and CND-WS hybrids were characterized by spectroscopic, thermal, and electron microscopy imaging methods. Based on electronic absorption and fluorescence emission spectroscopy, modulation of the optoelectronic properties of TMDs by interfacing with CNDs was accomplished. Electrochemical studies revealed facile oxidation of MoS over WS in the examined hybrids, suggesting it to be better electron donor. Excited state events, investigated by femtosecond transient absorption spectroscopic studies, revealed ultrafast energy transfer from photoexcited CNDs to both MoS and WS. Interestingly, upon MoS photoexcitation, charge transfer from an exciton dissociation path of MoS to CNDs, within CND-MoS, was observed. However, such a process in CND-WS was found to be absent due to energetic reasons. The present study highlights the importance of TM...
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Research Interests: Materials Science, Medicine, Porosity, Capacitance, QC, and 3 moreSupercapacitor, Carbon Fibers, and Electrode
X-ray scattering (XRS) experiments have been performed on multi-layered graphene oxide (GO) paper. GO can be easily hydrated as water naturally intercalates in the hydrophilic nanostructure. The effect of the intercalated water on the XRS... more
X-ray scattering (XRS) experiments have been performed on multi-layered graphene oxide (GO) paper. GO can be easily hydrated as water naturally intercalates in the hydrophilic nanostructure. The effect of the intercalated water on the XRS signals is measured during dehydration under thermal treatment in the temperature range 298–473 K as well as during hydration under saturated water vapour pressure. A simple modelling of the XRS signals by taking into account the presence and the type of intercalated water (bound water or physisorbed water) is introduced. It allows an explanation of the variations of intensity and position of XRS reflections observed experimentally.
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ABSTRACTWe report a novel, simple, and inexpensive method for preparing efficient carbon nanotube-based hydrogen sensors. Sensor devices were fabricated by simply spraying single-walled carbon nanotube (SWNT) dispersions on alumina... more
ABSTRACTWe report a novel, simple, and inexpensive method for preparing efficient carbon nanotube-based hydrogen sensors. Sensor devices were fabricated by simply spraying single-walled carbon nanotube (SWNT) dispersions on alumina substrates. Pd-functionalization of the employed SWNTs enabled increasing the device sensitivity to hydrogen. The effect of aging, thermal processing, and the employed carrier gases on the sensor performance is here described. The fabricated thin film sensors exhibited good sensitivity to hydrogen at room temperature in reversible and reproducible detection processes.
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Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, Digital.CSIC. Identificador, Frontiers in polymer science. International Symposium. 7-9 June 2009, Mainz (Germany). Identificador,... more
Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, Digital.CSIC. Identificador, Frontiers in polymer science. International Symposium. 7-9 June 2009, Mainz (Germany). Identificador, http://hdl.handle.net/10261/15074. ...