Listar Departament: Física por autoría "f91ca8b7-2f59-4583-a516-f4d4186c64ca"
Mostrando ítems 1-20 de 45
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A low temperature aqueous formate fuel cell using cobalt hexacyanoferrate as a non-noble metal oxidation catalyst
Han, Lijuan; González-Cobos, Jesús; Sánchez-Molina, Irene; Giancola, Stefano; Folkman, Scott; Gimenez, Sixto; Vidal-Ferran, Anton; Galan-Mascaros, Jose Ramon Royal Society of Chemistry (2020-12-01)Cobalt hexacyanoferrate, the Co–Fe Prussian blue derivative (CoFePB), is an effective, selective and stable electrocatalyst for formate oxidation, exhibiting robust performance under a variety of electrolyte conditions. ... -
Analysis of bio-anode performance through electrochemical impedance spectroscopy
Heijne, Annemiek ter; Schaetzle, Olivier; Gimenez, Sixto; Navarro, Lucia; Hamelers, Bert; Fabregat-Santiago, Francisco Elsevier (2015-12)In this paper we studied the performance of bioanodes under different experimental conditions using polarization curves and impedance spectroscopy. We have identified that the large capacitances of up to 1 mF·cm− 2 for ... -
Calculation of the Energy Band Diagram of a Photoelectrochemical Water Splitting Cell
Cendula, Peter; Tilley, S. David; Gimenez, Sixto; Bisquert, Juan; Schmid, Matthias; Grätzel, Michael; Schumacher, Jürgen O. American Chemical Society (2014-11)A physical model is presented for the semiconductor electrode of a photoelectrochemical cell. The model accounts for the potential drop in the Helmholtz layer and thus enables description of both band edge pinning and ... -
Carrier density and interfacial kinetics of mesoporous TiO2 in aqueous electrolyte determined by impedance spectroscopy
Gimenez, Sixto; Dunn, Halina K.; Rodenas, Pau; Fabregat-Santiago, Francisco; Miralles, Sara G.; Barea, Eva M; Trevisan, Roberto; Guerrero, Antonio; Bisquert, Juan Elsevier (2012)Water splitting at a semiconductor/solution interface with the only input of sunlight to generate hydrogen is one of the most attractive strategies to produce and store chemical energy. In the present study we have ... -
Competitive Photoelectrochemical Methanol and Water Oxidation with Hematite Electrodes
Klahr, Benjamin; Gimenez, Sixto; Zandi, Omid; Fabregat-Santiago, Francisco; Hamann, Thomas ACS Publications (2015-03-24)Photocatalytic water and methanol oxidation were studied at thin film hematite electrodes synthesized by atomic layer deposition (ALD). Systematic photoelectrochemical characterization along with O2 evolution measurements ... -
Controlled Carbon Nitride Growth on Surfaces for Hydrogen Evolution Electrodes
Shalom, Menny; Gimenez, Sixto; Schipper, Florian; Herraiz Cardona, Isaac; Bisquert, Juan; Antonietti, Markus Wiley (2014-04-01)Efficient and low-cost electrocatalysts for the hydrogen evolution reaction are highly desired for future renewable energy systems. Described herein is the reduction of water to hydrogen using a metal-free carbon nitride ... -
Easily manufactured TiO2 hollow fibers for quantum dot sensitized solar cells
Samadpour, Mahmoud; Gimenez, Sixto; Zad, Azam Iraji; Taghavinia, Nima; Mora-Sero, Ivan Royal Society of Chemistry (2011)TiO2 hollow fibers with high surface area were manufactured by a simple synthesis method, using natural cellulose fibers as template. The effective light scattering properties of the hollow fibers, originating from their ... -
Effect of nanostructured electrode architecture and semiconductor deposition strategy on the photovoltaic performance of quantum dot sensitized solar cells
Samadpour, Mahmoud; Gimenez, Sixto; Pérez Boix, Pablo; Shen, Qing; Calvo, Mauricio E.; Taghavinia, Nima; Iraji Zad, Azam; toyoda, taro; Míguez, Hernán; Mora-Sero, Ivan Elsevier (2012)Here we analyze the effect of two relevant aspects related to cell preparation on quantum dot sensitized solar cells (QDSCs) performance: the architecture of the TiO2 nanostructured electrode and the growth method of quantum ... -
Electrochemical and Photoelectrochemical Investigation of Water Oxidation with Hematite Electrodes
Klahr, Benjamin; Gimenez, Sixto; Fabregat-Santiago, Francisco; Bisquert, Juan; Hamann, Thomas Royal Society of Chemistry (2012-04)Atomic layer deposition (ALD) was utilized to deposit uniform thin films of hematite (α-Fe2O3) on transparent conductive substrates for photocatalytic water oxidation studies. Comparison of the oxidation of water to the ... -
Electron Lifetime in Dye-Sensitized Solar Cells: Theory and Interpretation of Measurements
Bisquert, Juan; Fabregat-Santiago, Francisco; Mora-Sero, Ivan; Garcia-Belmonte, Germà; Gimenez, Sixto American Chemical Society (2009)The electron lifetime τn in dye-sensitized solar cells (DSC) is a central quantity to determine the recombination dynamics in the solar cell. It can be measured by several methods: impedance spectroscopy, IMVS, stepped ... -
Energy Diagram of Semiconductor/Electrolyte Junctions
Bisquert, Juan; Cendula, Peter; Bertoluzzi, Luca; Gimenez, Sixto American Chemical Society (2013-12)In electrochemistry and photoelectrochemistry, it is most common to refer the voltage to a reference electrode (RE) or in a two-electrode cell with respect to a counterelectrode (CE).(1, 2) However, in a semiconductor film ... -
Energy transfer versus charge separation in hybrid systems of semiconductor quantum dots and Ru-dyes as potential co-sensitizers of TiO2-based solar cells.
Bisquert, Juan; Mora-Sero, Ivan; Gimenez, Sixto; Rogach, A. L.; Lutich, Andrey A.; Gross, Dieter; Poeschl, Andreas; Susha, A. S.; Lana-Villarreal, Teresa © 2011 American Institute of Physics (2011-07)Hybrid structures of colloidal quantum dots (QDs) with Ru-dyes have been studied as candidates for panchromatic sensitizers for TiO2-based solar cells. Steady-state and time resolved photoluminescence spectroscopy and ... -
Harnessing infrared photons for photoelectrochemical hydrogen generation. A PbS quantum dot based "quasi-artificial leaf"
Trevisan, Roberto; Rodenas, Pau; González Pedro, Victoria; Sima, Cornelia; S. Sánchez, Rafael; Barea, Eva M; Mora-Sero, Ivan; Fabregat-Santiago, Francisco; Gimenez, Sixto American Chemical Society (2013)Hydrogen generation by using quantum dot (QD) based heterostructures has emerged as a promising strategy to develop artificial photosynthesis devices. In the present study, we sensitize mesoporous TiO2 electrodes with ... -
High performing PbS Quantum Dot Sensitized Solar Cells exceeding 4% efficiency: The role of metal precursor in the electron injection and charge separation
González Pedro, Victoria; Sima, Cornelia; Marzari, Gabriela; Boix, Pablo P; Gimenez, Sixto; Qing, Shen; Dittrich, Thomas; Mora-Sero, Ivan Royal Society of Chemistry (2013)Here we report the preparation of high performance Quantum Dot Sensitized Solar Cells (QDSCs) based on PbS–CdS co-sensitized nanoporous TiO2 electrodes. QDs were directly grown on the TiO2 mesostructure by the Successive ... -
Hole conductivity and acceptor density of p-type CuGaO2 nanoparticles determined by impedance spectroscopy: The effect of Mg doping
Herraiz Cardona, Isaac; Fabregat-Santiago, Francisco; Renaud, Adèle; Julian-Lopez, Beatriz; Odobel, Fabrice; Carioc, Laurent; Jobic, Stéphane; Gimenez, Sixto Elsevier (2013)Delafossite materials like CuGaO2 have appeared as promising p-type semiconductor materials for their exploitation in tandem dye sensitized solar cells and water splitting photoelectrochemical cells. However, the intrinsic ... -
Impact of Oxygen Vacancy Occupancy on Charge Carrier Dynamics in BiVO4 Photoanodes
Selim, Shababa; Pastor , Ernest; García-Tecedor, Miguel; Morris, Madeleine; Francàs Forcada, Laia; Sachs, Michael; Moss, Benjamin; Corby, Sacha; Mesa, Camilo A.; Gimenez, Sixto; Kafizas, Andreas; Bakulin, Artem; Durrant, James American Chemical Society (2019-11-27)Oxygen vacancies are ubiquitous in metal oxides and critical to performance, yet the impact of these states upon charge carrier dynamics important for photoelectrochemical and photocatalytic applications remains contentious ... -
In situ investigation of dewaxing and sintering of stainless steel powder compacts by impulse excitation
Gimenez, Sixto; Vleugels, Jozef; Van der Biest, Omer Elsevier (2008)The dewaxing and sintering behaviour of 316LHD (high-density) powder metallurgy stainless steel grade have been in situ characterized by means of the high-temperature impulse excitation technique. The evolution of the E ... -
Influence of cysteine adsorption on the performance of CdSe quantum dots sensitized solar cells
XU, XUEQING; Gimenez, Sixto; Mora-Sero, Ivan; Abate, Antonio; Bisquert, Juan; Xu, Gang Elsevier (2010)The surface of mesoporous TiO<sub>2</sub> electrodes has been functionalized with cysteine using different solutions for the subsequent attachment of colloidal CdSe QDs solved in toluene. The adsorption behavior of both ... -
Interpretation of cyclic voltammetry measurements of thin semiconductor films for solar fuel applications
Bertoluzzi, Luca; Badia Bou, Laura; Fabregat-Santiago, Francisco; Gimenez, Sixto; Bisquert, Juan American Chemical Society (2013)A simple model is proposed that allows interpretation of the cyclic voltammetry diagrams obtained experimentally for photoactive semiconductors with surface states or catalysts used for fuel production from sunlight. When ... -
Lead Sulfide Nanocubes for Solar Energy Storage
Lemsi, Amira; Cardenas-Morcoso, Drialys; Haro, Marta; Gil Barrachina, Carlos; Aranda Alonso, Clara; Maghraoui Meherzi, Hager; García-Tecedor, Miguel; Gimenez, Sixto; Julian-Lopez, Beatriz Wiley (2020-04-23)Lead sulfide (PbS) nanocubes are produced by a very simple solvothermal procedure that uses a unique molecule, ethylenediamine, as solvent and capping ligand to control the size and shape of the nanocrystals. Detailed ...