References of "Henrist, Catherine"
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See detailSurface treatments for electrochromic glazing: toward reduced costs and optimal performances through ultrasonic spray pyrolysis
Maho, Anthony ULiege; Denayer, Jessica; Bister, Geoffroy et al

Conference (2015, May)

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See detailDeposition of electrochromic oxide films by surfactant-assisted ultrasonic spray pyrolysis
Maho, Anthony ULiege; Denayer, Jessica; Bister, Geoffroy et al

Conference (2015, May)

Detailed reference viewed: 33 (3 ULiège)
See detailPolymer electrolytes and adapted mesoporous TiO2 for Solid State Dye Sensitized Solar
Bharwal, Anil Kumar ULiege; Fannie, Alloin; Iojoiu, Cristina et al

Conference (2015, January)

Dye-sensitized solar cells (DSSC) have attracted a great attention due to their low production cost and high photo-conversion efficiencies since a new type of dye-sensitized solar cell has been reported ... [more ▼]

Dye-sensitized solar cells (DSSC) have attracted a great attention due to their low production cost and high photo-conversion efficiencies since a new type of dye-sensitized solar cell has been reported by Grätzel [1,2]. The electrolytes are one of the key components and their properties have much effect on the conversion efficiencies. An electrolyte containing a suitable redox couple plays a very important role in determining the photovoltaic characteristics and durability of DSSC. Although there is the inherent drawback of the cell due to the volatility and possible leakage problem of liquid electrolytes during the long-term out-door operation. Numerous efforts have been made to overcome this problem by replacing the liquid electrolytes with solid or quasi-solid state electrolytes composed of various polymers [3] and room temperature ionic liquids [4]. In this work, we report a new quasi-solid state polymer electrolyte based on polysiloxane consisting of imidazolium exhibiting higher ionic conductivity, good chemical, thermal and electrochemical stabilities. Three types of polymer electrolytes based on polysiloxane grafted with different ratio of imidazolium moieties and ionic liquids have been synthesized and characterized. Increasing the proportion of imidazolium moieties in polysiloxane increased the conductivity and viscosity of the polymer electrolyte respectively. The thermal stability of the polymer electrolytes is determined by thermogravimetric analysis. The porosity of the TiO2 photoanode plays a crucial role due to the requirement of excellent pore filling by the solid state electrolyte to ensure optimal interface. Therefore, TiO2 thin films with regular and large pores, designed for optimal electrolyte impregnation will be prepared using templating-assisted dip-coating methods. The objective of the present work is to develop in parallel the best formulation of polymer-based electrolyte and a highly porous TiO2 photo anode. The performances of those combined components will be evaluated in assembled DSSC, with commercial dyes and transparent conductive glasses. [1] M. Grätzel, Journal of Photochemistry and Photobiology C 4, 2003, 145. [2] A. Hagfeldt, M. Grätzel, Accounts of Chemical Research 33, 2000, 269. [3] J. Wu, Z. Lan, J. Lin, M. Huang, S. Hao, T. Sato, S. Yin, Advanced Materials 19, 2007, 4006. [4] M.C. Kroon, W. Buijs, C.J. Peters, G.J. Witkamp, Green Chemistry 8, 2006, 241. [less ▲]

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See detailPolysiloxane based polymer Electrolytes for Mesoporous TiO2 Solid State Dye Sensitised Solar Cell
Bharwal, Anil Kumar ULiege; Fannie, Alloin; Iojoiu, Cristina et al

Poster (2015)

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See detailPolysiloxane Electrolytes for Mesoporous TiO2 based Solid State Dye Sensitized Solar Cell
Bharwal, Anil Kumar ULiege; Fannie, Alloin; Iojoiu, Cristina et al

Poster (2015)

Dye-sensitized solar cells (DSSC) have attracted a great attention due to their low production cost and high photo-conversion efficiencies since a new type of dye-sensitized solar cell has been reported ... [more ▼]

Dye-sensitized solar cells (DSSC) have attracted a great attention due to their low production cost and high photo-conversion efficiencies since a new type of dye-sensitized solar cell has been reported by Grätzel [1, 2]. The electrolytes are one of the key components and their properties have much effect on the conversion efficiencies. An electrolyte containing a suitable redox couple plays a very important role in determining the photovoltaic characteristics and durability of DSSC. Although there is the inherent drawback of the cell due to the volatility and possible leakage problem of liquid electrolytes during the long-term out-door operation. Numerous efforts have been made to overcome this problem by replacing the liquid electrolytes with solid or quasi-solid state electrolytes composed of various polymers [3] and room temperature ionic liquids [4]. In this work, we report a new quasi-solid state polymer electrolyte based on polysiloxane consisting of imidazolium exhibiting higher ionic conductivity, good chemical, thermal and electrochemical stabilities. Three types of polymer electrolytes based on polysiloxane grafted with different ratio of imidazolium moieties and ionic liquids have been synthesized and characterized. Increasing the proportion of imidazolium moieties in polysiloxane increased the conductivity and viscosity of the polymer electrolyte respectively. The thermal stability of the polymer electrolytes is determined by thermogravimetric analysis. The porosity of the TiO2 photoanode plays a crucial role due to the requirement of excellent pore filling by the solid state electrolyte to ensure optimal interface. Therefore, TiO2 thin films with regular and large pores, designed for optimal electrolyte impregnation have been prepared using dual templating method. The techniques are derived from the classical Pluronic-templating synthesis of mesoporous TiO2 Anatase films [5]. The structural characterization of the TiO2 thin films have been done by techniques such as Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), XRD, etc.. The objective is to introduce a second population of pores to facilitate the accessibility of large species while keeping very high value of specific species. The performances of those combined components will be evaluated in assembled DSSC, with commercial dyes and transparent conductive glasses. [1] M. Grätzel, Journal of Photochemistry and Photobiology C 4, 2003, 145. [2] A. Hagfeldt, M. Grätzel, Accounts of Chemical Research 33, 2000, 269. [3] J. Wu, Z. Lan, J. Lin, M. Huang, S. Hao, T. Sato, S. Yin, Advanced Materials 19, 2007, 4006. [4] M.C. Kroon, W. Buijs, C.J. Peters, G.J. Witkamp, Green Chemistry 8, 2006, 241. [5] J. Zhao et al, Microporous and Mesoporous Materials 138, 2011, 200. [less ▲]

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See detailPolymer Electrolytes for Mesoporous TiO2 Solid State Dye Sensitized Solar Cell
Bharwal, Anil Kumar ULiege; Fannie, Alloin; Iojoiu, Cristina et al

Poster (2015)

Dye-sensitized solar cells (DSSC) have attracted a great attention due to their low production cost and high photo-conversion efficiencies since a new type of dye-sensitized solar cell has been reported ... [more ▼]

Dye-sensitized solar cells (DSSC) have attracted a great attention due to their low production cost and high photo-conversion efficiencies since a new type of dye-sensitized solar cell has been reported by Grätzel [1, 2]. The electrolytes are one of the key components and their properties have much effect on the conversion efficiencies. An electrolyte containing a suitable redox couple plays a very important role in determining the photovoltaic characteristics and durability of DSSC. Although there is the inherent drawback of the cell due to the volatility and possible leakage problem of liquid electrolytes during the long-term out-door operation. Numerous efforts have been made to overcome this problem by replacing the liquid electrolytes with solid or quasi-solid state electrolytes composed of various polymers [3] and room temperature ionic liquids [4]. In this work, we report a new quasi-solid state polymer electrolyte based on polysiloxane consisting of imidazolium exhibiting higher ionic conductivity, good chemical, thermal and electrochemical stabilities. Three types of polymer electrolytes based on polysiloxane grafted with different ratio of imidazolium moieties and ionic liquids have been synthesized and characterized. Increasing the proportion of imidazolium moieties in polysiloxane increased the conductivity and viscosity of the polymer electrolyte respectively. The thermal stability of the polymer electrolytes is determined by thermogravimetric analysis. The porosity of the TiO2 photoanode plays a crucial role due to the requirement of excellent pore filling by the solid state electrolyte to ensure optimal interface. Therefore, TiO2 thin films with regular and large pores, designed for optimal electrolyte impregnation have been prepared using dual templating method. The techniques are derived from the classical Pluronic-templating synthesis of mesoporous TiO2 Anatase films [5]. The structural characterization of the TiO2 thin films have been done by techniques such as Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), XRD, etc.. The objective is to introduce a second population of pores to facilitate the accessibility of large species while keeping very high value of specific species. The performances of those combined components will be evaluated in assembled DSSC, with commercial dyes and transparent conductive glasses. Acknowledgements: This work is supported by Communauté de recherche académique, ARC Rhône Alpes. References [1] M. Grätzel, Journal of Photochemistry and Photobiology C 4, 2003, 145. [2] A. Hagfeldt, M. Grätzel, Accounts of Chemical Research 33, 2000, 269. [3] J. Wu, Z. Lan, J. Lin, M. Huang, S. Hao, T. Sato, S. Yin, Advanced Materials 19, 2007, 4006. [4] M.C. Kroon, W. Buijs, C.J. Peters, G.J. Witkamp, Green Chemistry 8, 2006, 241. [5] J. Zhao et al, Microporous and Mesoporous Materials 138, 2011, 200. [less ▲]

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See detailTiO2 Macroscopic Fibers with Enhanced Photocatalytic Properties Obtained through a Scale-Up Semi-Industrial Process
Kinadjian, Natacha; Le Bechec, Mickael; Henrist, Catherine ULiege et al

in Advanced Engineering Materials (2015), 17(1), 36-44

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See detailPorous functional materials for energy applications
Colson, Pierre ULiege; Dewalque, Jennifer ULiege; Maho, Anthony ULiege et al

Conference (2015)

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See detailElucidating the opto-electrical properties of solid and hollow titania scattering layers for improvement of dye-sensitized solar cells
Thalluri, Venkata Visveswara Gopala Kris; Henrist, Catherine ULiege; Spronck, Gilles ULiege et al

in Thin Solid Films (2015)

The light scattering method has been adapted in dye-sensitized solar cells (DSCs) for optical absorption enhancement. In DSC's, particle-size of TiO2 should be inline with the scattering wavelength range ... [more ▼]

The light scattering method has been adapted in dye-sensitized solar cells (DSCs) for optical absorption enhancement. In DSC's, particle-size of TiO2 should be inline with the scattering wavelength range. Scattering particles can be used either by forming a bilayer structure with TiO2 nanocrystalline film or into the bulk of TiO2 nanocrystalline film. For improving the DSCs performances these scattering layers aim to refract/reflect the incident light by extending the traveling distance of UV-Visible/near-IR light within the dye-sensitized TiO2 nanocrystalline film. In this work, the scattering layers with two different particle-sizes (~200 nm-solid and ~400 nm-hollow) were deposited as an additional layer on the top of dye-sensitized TiO2 nanocrystalline film and the morphological properties were studied. By using various opto-electrical characterization techniques, the influence of these scattering layers for two different classes of DSCs prepared from N3 (UV-Vis) and SQ2 (near-IR) dyes were investigated. [less ▲]

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See detailComparison of structural features of spin-coated and USP-deposited templated α-Fe2O3films
Toussaint, Caroline ULiege; Chatzikyriakou, Daphne; Cloots, Rudi ULiege et al

Poster (2015)

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See detailCombining mesoporosity and Ti-doping in hematite films for water splitting
Toussaint, Caroline ULiege; Tran, Hoang Son ULiege; Colson, Pierre ULiege et al

in Journal of Physical Chemistry C (2015), 119(4), 1642-1650

(Graph Presented). In this study, we report the synthesis of Ti-doped mesoporous hematite films by soft-templating for application as photoanodes in the photoelectrolysis of water (water splitting ... [more ▼]

(Graph Presented). In this study, we report the synthesis of Ti-doped mesoporous hematite films by soft-templating for application as photoanodes in the photoelectrolysis of water (water splitting). Because the activation of the dopant requires a heat treatment at high temperature (≥800°C), it usually results in the collapse of the mesostructure. We have overcome this obstacle by using a temporary SiO2 scaffold to hinder crystallite growth and thereby maintain the mesoporosity. The beneficial effect of the activated dopant has been confirmed by comparing the photocurrent of doped and undoped films treated at different temperatures. The role of the mesostructure was investigated by comparing dense, collapsed, and mesoporous films heated at different temperatures and characterized under front and back illumination. It turns out that the preservation of the mesotructure enables a better penetration of the electrolyte into the film and therefore reduces the distance that the photogenerated holes have to travel to reach the electrolyte. As a result, we found that mesoporous films with dopant activation at 850°C perform better than comparable dense and collapsed films. [less ▲]

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See detailInnovative materials improving energy efficiency of buildings
Dewalque, Jennifer ULiege; Denayer, Jessica ULiege; Schrijnemakers, Audrey ULiege et al

Conference (2014, July 01)

Detailed reference viewed: 40 (18 ULiège)
See detailElectrografting of polythiophenes on zinc oxide nanorods for photovoltaic cells
Demarteau, Jérémy ULiege; Ouhib, Farid ULiege; Henrist, Catherine ULiege et al

Poster (2014, May 20)

As the rarefaction of fossil energies, photovoltaic cells are certainly amongst the most important energy sources for the future. Our work concentrated on hybrid photovoltaic cells that are based on ... [more ▼]

As the rarefaction of fossil energies, photovoltaic cells are certainly amongst the most important energy sources for the future. Our work concentrated on hybrid photovoltaic cells that are based on organic (polythiophene) and inorganic components (ZnO nanorods). The technology that maximizes the contact area between the two semi-conductor n and p while maintaining two separate components is the interdigital configuration. As the inorganic part, perfectly well aligned zinc oxide (ZnO) 1D nanostructures have been synthesized by hydrothermal growth on ZnO-seeded FTO substrates. SEM, AFM and XRD characterizations evidence patterned well- aligned nanorods with high c-axis, their roughness of surface and the length of their nanostructure. Concerning the organic component, we synthetize polythiophenes based diblock copolymer with high degree of regioregularity and predetermined molecular weight using Grignard Methatis (GRIM) process. Diblock polythiophene based copolymers are of interest because of the possibility of generating multifunctional materials (by associating the specific properties of each block), including their ability for self-assembly into well-defined nanostructures (fibrils or micelles) with controllable dimensions. Poly(3-hexylthiophene) (P3HT) composes the first block and the second block is either a polythiophene bearing an acrylate group on each monomer unit (PAcET), or a polythiophene bearing both acrylate and poly(ethylene glycol) side chains (P(AcET-co-PEGET)). Typically, the acrylates are used to fixe in a covalent way the copolymer to ZnO nanorods, while the PEG grafts are necessary for the solubilisation of the copolymer in the electrografting medium. 1H NMR and DLS characterizations allow us to find the backbone and the micellar structure of the copolymer. Cathodic polarization (electrografting) of ZnO nanorods induces electropolymerization of acrylate groups, leading to an adherent organized film of poly(thiophene)-based micelles. During the illumination tests, we obtained a typical response of a photovoltaic despite the low yields. This promising synthetic route opens exciting perspectives for the production and the electrochemical functionalization of different lengths of ZnO nanowires, which seems to be promising candidate for hybrids photovoltaic cells. [less ▲]

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See detailPolymer Electrolytes for Solid State Dye Sensitised Solar Cell
Bharwal, Anil Kumar ULiege; Alloin, Fannie; Iojoiu, Cristina et al

Poster (2014)

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See detailYBa2Cu3O7-δ thick films for magnetic shielding: Electrophoretic deposition from butanol-based suspension
Closset, Raphaël ULiege; Kumar, Devendra; Wera, Laurent ULiege et al

in Materials Letters (2014), 119

Multilayered YBa2Cu3O7-δ (YBCO) thick films were coated on silver substrates by electrophoretic deposition (EPD) followed by heat treatment. A butanol-based YBCO suspension is used instead of the common ... [more ▼]

Multilayered YBa2Cu3O7-δ (YBCO) thick films were coated on silver substrates by electrophoretic deposition (EPD) followed by heat treatment. A butanol-based YBCO suspension is used instead of the common acetone-iodine combination. Tests with several dispersing agents reveal that a branched polyethyleneimine (PEI) dispersant develops large positive surface charge on suspended YBCO particles. As a demonstration of the performance of this new suspension formulation, a 12-layer 100 μm-thick YBCO coating was deposited on an Ag tube. The superconducting transition is sharp with onset critical temperature at 92 K. The sample can shield a magnetic field of ~1.3 mT at 77 K, i.e., the best value so far for an YBCO coating on a metallic substrate. © 2013 Elsevier B.V. [less ▲]

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See detailInfluence of mesoporosity in hematite films on water splitting efficiency
Toussaint, Caroline ULiege; Cloots, Rudi ULiege; Henrist, Catherine ULiege

Poster (2014)

Solar energy is inexhaustible but variable during the day and the seasons. Photoelectrolysis of water (water splitting) convert this energy into hydrogen to obtain an energy that can be stored and ... [more ▼]

Solar energy is inexhaustible but variable during the day and the seasons. Photoelectrolysis of water (water splitting) convert this energy into hydrogen to obtain an energy that can be stored and transported on demand. Hematite is a promising material for the photoanode in water splitting because of its high stability in water, cheapness, abundance and its band gap that enables the absorption of visible light (Eg: 2,1eV). Nevertheless, hematite has also some drawbacks including a short diffusion length of holes and a bad electronic conductivity. We have implemented spin coating and templating to produce doped mesoporous hematite films. The nanostructuration can improve the performances in water splitting by reducing the diffusion length of holes and increasing the specific surface between the film and the electrolyte. To suppress the collapse of the mesoporosity at high temperature (requested for dopant activation), we have used a temporary silica confinement scaffold that reduces the crystallite growth. To show the impact of the nanostructure, we have compared three films (mesoporous, collapsed and dense) in terms of hematite content (elemental analysis), nanostructure (electron microscopy), crystallinity (X-ray diffraction) and water splitting efficiency. We have also test two thermal treatments. This study highlights the effect of the effective interface with the electrolyte, through the preservation or not of open porosity and the different evolutions of the nanostructures as a function of the heat treatment. [less ▲]

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See detailMesoporous amorphous tungsten oxide electrochromic films: a Raman analysis of their good switching behavior
Chatzikyriakou, Dafni ULiege; Krins, Natacha ULiege; Gilbert, Bernard ULiege et al

in Electrochimica Acta (2014), 137

The intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics. In this study, we ... [more ▼]

The intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics. In this study, we prepared two types of amorphous films via the sol-gel technique: one dense and one mesoporous in order to compare their response upon lithium intercalation and de-intercalation. According to chronoamperometric measurements, Li+ intercalates/de-intercalates faster in the mesoporous film (24s/6s) than in the dense film (48s/10s). The electrochemical measurements (cyclic voltammetry and chronoamperometry) also showed worse reversibility for the dense film compared to the mesoporous film, giving rise to important Li+ trapping and remaining coloration of the film. Raman analysis showed that the mesoporous film provides more accessible and various W-O surface bonds for Li+ intercalation. On the contrary, in the first electrochemical insertion and de-insertion in the dense film, Li+ selectively reacts with a few surface W-O bonds and preferentially intercalates into pre-existing crystallites to form stable irreversible LixWO3 bronze. [less ▲]

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