References of "Mahy, Julien"
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See detailAmbient temperature ZrO2-doped TiO2 crystalline photocatalysts: Highly efficient powders and films for water depollution
Mahy, Julien ULiege; Lambert, Stéphanie ULiege; Tilkin, Rémi ULiege et al

in Materials Today Energy (2019), 13

In this paper, several TiO2 materials doped with zirconia precursor (0.7, 1.4, 1.6 and 2.0 mol%) were synthesized by an easy aqueous sol-gel synthesis at ambient temperature. This method consisted in the ... [more ▼]

In this paper, several TiO2 materials doped with zirconia precursor (0.7, 1.4, 1.6 and 2.0 mol%) were synthesized by an easy aqueous sol-gel synthesis at ambient temperature. This method consisted in the peptization of the TiO2 colloid in presence of HNO3. The corresponding pure TiO2 material was also synthesized for comparison. The performances and the physico-chemical properties of these materials were compared to the well-known Evonik P25 photocatalyst. The physico-chemical characterizations showed that nano-crystalline anatase-brookite particles were produced with the sol-gel process, with higher specific surface area than P25 (∼200 m2 g-1 vs. 47 m2 g-1). All samples presented a higher visible absorption than P25. The XPS spectra showed that all the samples were doped with nitrogen and that mixed TiO2–ZrO2 oxide materials were obtained when doping with zirconia precursor. Photoactivity was evaluated through the degradation of p-nitrophenol in water. On the one hand, under UV/visible light, the ZrO2 doping increased the degradation efficiency of the pure TiO2 catalyst due to a better charge separation in the mixed TiO2–ZrO2 oxides. The activity of the sample with the highest dopant content was even higher than the one of P25. On the other hand, under visible light, all samples were much more efficient than P25. This activity shift towards visible range was due to the N-doping of the catalysts, with a slight improvement for the doped ones. Finally, the feasibility of producing films starting from an aqueous suspension of the photocatalyst was assessed on P25, pure TiO2 and the best doped material. The photoactivity of these films, evaluated on the degradation of methylene blue under UV-A light, showed that the sample with the highest dopant concentration had an efficiency 4 times higher than pure TiO2 and 20 times higher than P25. [less ▲]

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See detailN, Fe single-doped and N-Fe co-doped TiO2 increasing photoactivity under visible light
Douven, Sigrid ULiege; Mahy, Julien ULiege; Lambert, Stéphanie ULiege

Conference (2019, June 20)

Nowadays, environmental pollution is a major concern in our society and numerous researches are realized to treat water, air and soil pollution. Among the different methods developed to reduce pollution ... [more ▼]

Nowadays, environmental pollution is a major concern in our society and numerous researches are realized to treat water, air and soil pollution. Among the different methods developed to reduce pollution, photocatalysis is a way to degrade organic pollutants. The most widely used photocatalyst is TiO2. For several years, the sol-gel synthesis has proven effective for the synthesis of TiO2 in the form of powders or films. Aqueous and non-aqueous methods can be used to produce TiO2 by sol-gel process. Regarding the cost and the environmental impact, the aqueous way seems to be the best way to produce large amount of TiO2 materials. The aim of the present work is to develop new formulation of doped and co-doped TiO2 to extend the activity towards visible region with optimal production costs and to improve the dopant content in order to maximize the photocatalytic activity. This study presents results with catalysts powders, but the final aim is to produce doped TiO2 films as previously successfully developed. [less ▲]

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See detailVisible Light Sensitive SnO2/ZnCo2O4 Material for the Photocatalytic Removal of Organic Pollutants in Water
Benhebal, Hadj; Wolfs, Cédric ULiege; Kadi, Samir et al

in Inorganics (2019), 7

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See detailNi-doped γ-Al2O3 as secondary catalyst for bio-syngas purification: influence of Ni loading, catalyst preparation and gas composition on catalytic activity
Claude, Vincent; Mahy, Julien ULiege; Geens, Jérémy ULiege et al

in Materials Today Chemistry (2019), 13

In this work, Ni/γ-Al2O3 catalysts were prepared by sol-gel methods with different Ni loadings (10 to 50 wt.%) and used as secondary catalyst for the steam reforming of toluene. A sample prepared by wet ... [more ▼]

In this work, Ni/γ-Al2O3 catalysts were prepared by sol-gel methods with different Ni loadings (10 to 50 wt.%) and used as secondary catalyst for the steam reforming of toluene. A sample prepared by wet impregnation with 10 wt.% of Ni was also synthesized and compared to the corresponding sol-gel sample. This study was divided in three main parts: the comparison of catalysts prepared by sol-gel process and impregnation, the influence of the gas composition on the catalytic performance of the sol-gel 10 wt.% Ni/γ-Al2O3 catalyst and the influence of Ni loading on the catalytic activity. When sol-gel and impregnated samples are compared, the impregnated catalyst showed a high initial toluene conversion followed by a consequent and progressive deactivation. Contrarily, the sol-gel catalyst showed a stable catalytic activity and relatively low carbon deposit. Indeed, before the steam reforming of toluene at 650 °C, the sol-gel catalyst was only calcined and no reduction step was realized to reduce nickel oxide. So this sample was reduced during the catalytic test at 650 °C. Moreover, it was observed that, if toluene was withdrawn from the syngas mixture during the catalytic test, the sol-gel sample was progressively re-oxidized by CO2 and H2O, leading to higher deactivation. As the Ni loading increased, the nickel oxide with strong interactions (NiAl2O4) was progressively joined by nickel oxide with low interactions (NiO/Al2O3) and bulk nickel oxide (NiO). This led to a high initial conversion of toluene, but also to a progressive loss of the catalytic activity throughout the catalytic test. It was shown that the sol-gel method developed throughout this work allowed preparing micro/mesoporous Ni/γ-Al2O3 catalysts with a high dispersion of Ni nanoparticles. [less ▲]

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See detailOptimization of Synthesis Parameters for the Production of Biphasic Calcium Phosphate Ceramics via Wet Precipitation and Sol‐Gel Process
Tilkin, Rémi ULiege; Mahy, Julien ULiege; Regibeau, Nicolas ULiege et al

in ChemistrySelect (2019), 4(21), 6634-6641

During the past few years, bioceramics, like hydroxyapatite and β‐tricalcium phosphate have been widely developed for bone reconstruction. These materials have to meet strict criteria regarding ... [more ▼]

During the past few years, bioceramics, like hydroxyapatite and β‐tricalcium phosphate have been widely developed for bone reconstruction. These materials have to meet strict criteria regarding biocompatibility, degradability, and mechanical properties. This work has been focusing on the influence of synthesis parameters on the production of calcium phosphate mixes, called biphasic calcium phosphate. In this optic, powders obtained from two synthesis processes (i. e. wet precipitation and sol‐gel process) were produced. The influence of pH, Ca/P molar mixing ratio, and calcination temperature was studied. These new materials were characterized in terms of composition, thermal properties, and textural properties via X‐ray diffraction, infrared spectroscopy, scanning electronic microscopy, thermogravimetric analysis, and nitrogen adsorption‐desorption. Wet precipitation technique produces in situ mixes with different hydroxyapatite contents while the sol‐gel process ends up with ceramics contaminated by cytotoxic CaO. Wet precipitation has been demonstrated more successful to control in situ mixes with specific composition. [less ▲]

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See detailAdvanced oxidative treatment for wastewater contaminated by micropollutants
Mahy, Julien ULiege; Vreuls, Christelle ULiege; Drot, Stéphane et al

Conference (2019, June 06)

Pharmaceuticals, personal care products, pesticides and other chemicals used for domestic purpose or industrial or agro-food production are continuously discharged into wastewater and lead to global ... [more ▼]

Pharmaceuticals, personal care products, pesticides and other chemicals used for domestic purpose or industrial or agro-food production are continuously discharged into wastewater and lead to global contamination of the aquatic environment all over Europe[1]. Removal during conventional wastewater treatment is unsatisfactory knowing that only 20 to 50% of micropollutants are removed in current waste water treatment plants[2]. The objective of the AOPTi project is to develop and validate an innovative technology to ensure efficient elimination of different types of micropollutants and toxic effects in waste water. The process is a tertiary treatment process, which can be easily integrated into municipal and industrial WWTPs. It is an economical physico-chemical treatment step after the conventional biological treatment[3]. The process is based on oxidation by ozone and a subsequent photocatalytic treatment. The technology is developed for companies involved in the water purification sector and for companies with toxic effluents loaded with micropollutants. Process parameters have to be determined depending on the type of waste water in order to lead to almost total degradation of all micropollutants and to ensure absence of toxicity of the resulting water. Treated water will be characterized in term of chemical transformation products (TPs) and toxicity. [less ▲]

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See detailAdvanced oxidative treatment for wastewater contaminated by micropollutants
Mahy, Julien ULiege; Vreuls, Christelle ULiege; Drot, Stéphane et al

Conference (2019, April 22)

Many micropollutant products are introduced into the environment by domestic, industrial or hospital waste waters. It has been observed that many of them are not well removed by traditional biological ... [more ▼]

Many micropollutant products are introduced into the environment by domestic, industrial or hospital waste waters. It has been observed that many of them are not well removed by traditional biological waste water treatment plants (WWTP). In this project, a physico-chemical process is elaborated and placed at the end of existing WWTP. Such processes already exist and are based on an ozone and UV radiation combination to oxidize organic compounds. Our study shows that higher degradations could be reached using heterogeneous photocatalysis in addition to ozone and UV radiation. At the laboratory scale, problematic micropollutants of the European Water Framework Directive have been chosen to model waste water (10 μg/L): pharmaceuticals (diclofenac, carbamazepin, sulfamethoxazol), PFOS, anti-corrosive (1H-Benzotriazol), phthalate (DEHP), alkylphenol (bisphenol A), pesticide (diuron, atrazine), flame retardant (PBDE). Their degradations were evaluated by LC-MS/MS and GC-MS/MS. Different photocatalysts have been synthesized by organic and aqueous sol-gel methods and deposited as thin films by dip-coating on glass substrate: pure titanium dioxide (TiO2) and doped titanium dioxide (with Ag, Pt, Commercial Evonik P25, MnO2 - nanoparticles, and with Zn2+ ions). Characterizations were made by profilometry for films thickness and roughness, by GIRXD for photoactive crystalline phase presence, by UV-Vis transmission for band-gap, by ICP-AES/MS for dopants percentages in films and in water (leaching concentration through delamination). The photoactivity of all these catalysts were determined from the degradation on 10 micropollutants (10 µg/L) under UV-C for 1 h. The best photocatalyst found was silver doped titanium dioxide. A film was then deposited inside a one-meter long alkaline-free tube for pilot trials. Experiments were carried out with 150 L of our model water (10 micropollutants with 10 µg/L) and with 150 L of waste water at the exit of a WWTP. Both experiments have confirmed laboratory results for efficient degradation of pharmaceutical products in water. [less ▲]

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See detailHydrodechlorination and complete degradation of chlorinated compounds with the coupled action of Pd/SiO2 and Fe/SiO2 catalysts: towards industrial catalyst synthesis conditions
Mahy, Julien ULiege; Tasseroul, Ludivine; Tromme, Olivier et al

in Journal of Environmental Chemical Engineering (2019), 7(1),

In this study, Pd/SiO2 and Fe/SiO2 catalysts have been synthesized by the cogelation process for hydrodechlorination applications. Different synthesis conditions were tested to approach the industrial ... [more ▼]

In this study, Pd/SiO2 and Fe/SiO2 catalysts have been synthesized by the cogelation process for hydrodechlorination applications. Different synthesis conditions were tested to approach the industrial conditions using industrial grade reactants and ambient air drying. The influence of these changes have been studied on the texture and the catalytic activity of the catalysts. The resulting materials are composed of metallic (Pd catalysts) or metallic oxide (Fe catalysts) nanoparticles highly dispersed in porous silica. The catalysts present a high specific surface area (between 250 and 500 m2/g) with a large pore size range between micro-, meso- and macropores. The modifications of the synthesis conditions give catalysts with similar textural properties compared to lab-scale catalysts. The catalytic activity of the binary catalysts have been evaluated on the hydrodechlorination of the 2,4,6-trichlorophenol (TCP) in water. Results show that Pd/SiO2 catalysts are able to dechlorinate the TCP and that Fe/SiO2 materials are able to degrade the resulting phenol. So this process allows a complete degradation of TCP. Industrial conditions catalysts show also similar catalytic results compared to lab-scale catalysts for the hydrodechlorination of the 2,4,6-trichlorophenol (TCP) in water. [less ▲]

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See detailAssessment of Advanced Photocatalytic Oxidation process for Micropollutant Elimination in Municipal and Industrial Waste Water Treatment Plants
Mahy, Julien ULiege; Vreuls, Christelle ULiege; Drot, Stéphane et al

Conference (2019, March 20)

Pharmaceuticals, personal care products, pesticides and other chemicals used for domestic purpose or industrial production are continuously discharged into wastewater and lead to global contamination of ... [more ▼]

Pharmaceuticals, personal care products, pesticides and other chemicals used for domestic purpose or industrial production are continuously discharged into wastewater and lead to global contamination of the aquatic environment all over Europe [1]. Removal during conventional wastewater treatment is unsatisfactory knowing that only 20 to 50% of micropollutants are removed in current waste water treatment plants [2]. Analytical methods become more and more sensitive so that traces of organic compounds are nowadays detected in waste, surface and ground waters. The Water Framework Directive listed 45 priority substances to be controlled. Two hormones and one painkiller have been added in 2013 in this directive as well as three antibiotics macrolides, one pesticide, one anti-UV and one anti-oxidant in 2015. The objective of the AOPTi project is to develop and validate an innovative technology to ensure efficient elimination of different types of micropollutants and toxic effects in waste water. Relevance and behaviour of transformation products in the treated water is investigated as second issue. The process is a tertiary treatment process, which can be easily integrated into municipal and industrial WWTPs. It is an economical physico-chemical treatment step after the conventional biological treatment [3]. The process is based on oxidation by ozone and a subsequent photocatalytic treatment combined with a biological active adsorption step as final finishing process. The technology is developed for companies involved in the water purification sector and for companies with toxic effluents loaded with micropollutants. Process parameters have to be determined depending on the type of waste water in order to lead to almost total degradation of all micropollutants and to ensure absence of toxicity of the resulting water. Treated water will be characterized in term of chemical transformation products (TPs) and toxicity. [less ▲]

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See detailPorphyrin-based hybrid silica-titania as a visible-light photocatalyst
Mahy, Julien ULiege; Pàez Martinez, Carlos ULiege; Carcel, Carole et al

in Journal of Photochemistry and Photobiology A: Chemistry (2019), 373

A silylated porphyrin derivative is co-hydrolyzed with Ti(OiPr)4 to produce a hybrid TiO2 photocatalyst, and three different ratios between porphyrin and TiO2 are made. In this way, the porphyrin ... [more ▼]

A silylated porphyrin derivative is co-hydrolyzed with Ti(OiPr)4 to produce a hybrid TiO2 photocatalyst, and three different ratios between porphyrin and TiO2 are made. In this way, the porphyrin fragments are held in the resulting matrix through strong Si-O-Ti covalent bonds to limit porphyrin leaching. Thanks to its photoactive character the porphyrin fragment can act as an actuator for the TiO2 to degrade organic pollutants using light from ultra-violet to the visible range. The photocatalysts are synthesized using an easy aqueous route allowing “green conditions” for synthesis. For comparative purposes, the corresponding pure TiO2 and a grafted catalyst are also synthesized and studied. For all samples, a mixture of anatase/brookite TiO2 is obtained, resulting in crystalline materials with low temperature synthesis. The three porphyrin-doped samples prepared in water prove to be efficient photocatalysts for the degradation of p-nitrophenol (PNP) under visible light, and an improvement in photoactivity is observed when the amount of porphyrin increases. The photocatalyst activity is very stable over time as the PNP degradation remains nearly constant after 264 h of testing, showing no leaching of porphyrin. In recycling tests, the grafted sample presents bond breaking between POR-Si and TiO2 and a decrease in photoactivity towards pure TiO2 sample activity. A comparison with the commercial Evonik P25 catalyst shows that the porphyrin-doped TiO2 is nearly 6 times more photoactive under visible light for PNP degradation. [less ▲]

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See detailSol-gel syntheses of photocatalysts for the removal of pharmaceutical products in water
Belet, Artium ULiege; Wolfs, Cédric ULiege; Mahy, Julien ULiege et al

in Nanomaterials (2019), 9

A screening study on seven photocatalysts was performed to identify the best candidate for pharmaceutical products degradation in water. Photocatalysts were deposited as thin films through a sol-gel ... [more ▼]

A screening study on seven photocatalysts was performed to identify the best candidate for pharmaceutical products degradation in water. Photocatalysts were deposited as thin films through a sol-gel process and subsequent dip-coating on glass slides. The efficiency of each photocatalyst was assessed through the degradation of methylene blue first, and then, through the degradation of fifteen different pharmaceutical products. Two main types of synthesis methods were considered: aqueous syntheses, where the reaction takes place in water, and organic syntheses, where reactions take place in an organic solvent and only a stoichiometric amount of water is added to the reaction medium. Photocatalysts synthesized via aqueous sol-gel routes showed relatively lower degradation efficiencies; however, the organic route required a calcination step at high temperature to form the photoactive crystalline phase, while the aqueous route did not. The best performances for the degradation of pharmaceuticals arose when Evonik P25 and silver nanoparticles were added to TiO2, which was synthesized using an organic solvent. In the case of methylene blue degradation, TiO2 modified with Evonik P25 and TiO2 doped with MnO2 nanoparticles were the two best candidates. [less ▲]

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See detailDurable photocatalytic thin coatings for road applications
Mahy, Julien ULiege; Pàez Martinez, Carlos ULiege; Hollevoet, Jonas et al

in Construction and Building Materials (2019), 215

In this study, 6 different coatings have been developed as photocatalytic coatings based on TiO2, which can be applied to concrete for road applications. The goal of these coatings is to degrade ... [more ▼]

In this study, 6 different coatings have been developed as photocatalytic coatings based on TiO2, which can be applied to concrete for road applications. The goal of these coatings is to degrade pollutants such as nitrogen oxides and volatile organic compounds emitted by road transport. The coatings are synthesized by sol-gel process in organic or water solvent or by a functionalization technique with hydroxybenzoic acid on commercial TiO2 nanoparticles (P25). These suspensions are deposited by dip-coating or spray-coating on three different concrete substrates: pavement blocks, brushed or exposed aggregates road concrete. For each process, particular attention has been paid to the development of TiO2 synthesis that will be easily produced on a larger scale. The samples are characterized with photocatalytic test on NOx degradation, mechanical resistance test and resistance to freeze-thaw cycles in presence of de-icing salts. Except from the samples resulting from the sol-gel organic route, all other samples show a NOx degradation between 10 and 45%. From resistance point of view, the best coating is the TiO2 P25/E coating synthesized by functionalization of P25 nanoparticles. Results highlight that anatase TiO2 is well present at the surface of the sample and an optimal TiO2 loading exists for this coating. The TiO2 P25/E coating shows promising properties for road applications. [less ▲]

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See detailSynthesis of Ni/γ-Al2O3-SiO2 catalysts with different silicon precursors for the steam toluene reforming
Claude, Vincent; Mahy, Julien ULiege; Geens, Jérémy ULiege et al

in Microporous and Mesoporous Materials (2019), 284

This work investigated the intrinsic properties and performances of Ni/γ-Al2O3-SiO2 modified with different silicon precursors for the steam reforming of toluene in biomass gasifier exit conditions (8000 ... [more ▼]

This work investigated the intrinsic properties and performances of Ni/γ-Al2O3-SiO2 modified with different silicon precursors for the steam reforming of toluene in biomass gasifier exit conditions (8000 ppmv of toluene, 650 °C). Samples were synthesized by an aqueous sol-gel process in presence of aluminum nitrate, nickel nitrate and the use of either tetramethoxysilane (TMOS, Si-(OCH3)4) or tetraethoxysilane (TEOS, Si-(OC2H5)4) in order to understand the influence of the reactivity of the silicon precursor. Furthermore, the use of N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS, (OCH3)3-Si-(CH2)3-NH-(CH2)2-NH2) is also investigated in order to understand the influence of a silicon precursor containing an ethylenediamine group, able to complex Ni2+ ions. By the chelation of Ni2+ ions by ethylenediamine groups during the synthesis, Ni/γ-Al2O3-SiO2 samples modified with EDAS showed higher dispersion of the metallic Ni nanoparticles and the higher resistance against the sintering of Ni particles. This was also attributed to the high microporous volume and the narrow mesoporous distribution of the support, which could also prevent the migration of the metallic Ni nanoparticles. The catalytic tests revealed that the reactivity of the silicon precursor played a major role on the conversion of toluene. For alumina supports modified with a silicon precursor with a low reactivity such as TEOS, the low integration of the Si atoms inside the bulk alumina lead to a slightly higher catalytic activity, but also to a high formation of structured carbon. The opposite effect was observed for the samples modified with a highly reactive silicon precursor, such as TMOS or EDAS, which showed a slightly lower catalytic activity, but a higher resistance against coking compared to pure Ni/γ-Al2O3 catalysts. [less ▲]

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See detailTailored films and biomaterials: another reality
Mahy, Julien ULiege; Wolfs, Cédric ULiege; Tilkin, Rémi ULiege et al

Poster (2018, December 10)

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See detailModification inorganique d’une argile locale: Application au traitement des eaux
Benhebal, Hadj; Kadi, Samir; Lellou, Salima et al

Poster (2018, December)

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See detailElaboration de matériaux zéolithiques à partir d'argiles locales: Application au traitement des eaux
Benhebal, Hadj; Kadi, Samir; Lellou, Salima et al

Poster (2018, December)

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See detailEasy-cleaning and photocatalytic materials
Mahy, Julien ULiege; léonard, Géraldine; Zubiaur, Anthony ULiege et al

Conference (2018, November 20)

Dans ce travail, un procédé sol-gel en phase aqueuse a été développé pour produire à grande échelle un photocatalyseur à base de TiO2 présentant des propriétés hydrophiles et une activité photocatalytique ... [more ▼]

Dans ce travail, un procédé sol-gel en phase aqueuse a été développé pour produire à grande échelle un photocatalyseur à base de TiO2 présentant des propriétés hydrophiles et une activité photocatalytique élevée pour la dépollution de l'eau et de l'air. La première étape consistait à développer une synthèse sol-gel en phase aqueuse de TiO2 pur à l'échelle du laboratoire. Le protocole de synthèse a été simplifié pour réduire le temps de synthèse, la température et le nombre d’étapes comme les étapes de lavage. Les propriétés physico-chimiques et photocatalytiques du matériau obtenu ont été caractérisées pour évaluer la production d'un revêtement hydrophile sur acier inoxydable et la formation d'un photocatalyseur efficace sur la dégradation de trois polluants (bleu de méthylène, p-nitrophénol ou acétaldéhyde) sous différentes formes (film ou poudre) et dans différentes phases (liquide ou gazeuse). Dans la deuxième partie, la synthèse aqueuse a été adaptée pour produire des catalyseurs de TiO2 dopés avec des ions Fe3+, Ag+, Cu2+, Zn2+, Cr3+, Al3+, Mn2+ et Co2+ et des nanoparticules métalliques de Pt afin d'améliorer leur activité. Certains dopants ont montré une photoactivité accrue et certains mécanismes ont été proposés pour expliquer ces modifications de l'activité avec le dopage. En outre, la comparaison des coûts à l'échelle du laboratoire a montré que le dopage au Zn2+ pouvait être envisagé pour des applications industrielles. En utilisant cette méthode, un photocatalyseur de TiO2 dopé au Zn a été synthétisé à grande échelle et a montré des propriétés homologues au produit à l'échelle du laboratoire. La troisième étape consistait à étudier la propriété de redispersion des colloïdes de TiO2 nanocristallins. En effet, les poudres obtenues par séchage sous air de ces colloïdes peuvent être redispersées dans l'eau pour produire des colloïdes qui sont comparés à ceux obtenus initialement. Cinq cycles de séchage-redispersion ont été réalisés sur des colloïdes sélectionnés. Un mécanisme a été proposé pour expliquer cette propriété intéressante, l'acide présent dans la synthèse semble être le facteur principal. Cela peut être très utile pour une application industrielle de cette synthèse permettant de réduire le volume et le poids pour le transport et le stockage. [less ▲]

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See detailAqueous N-Doped TiO2 Catalysts for Visible Light Photocatalytic Applications
Mahy, Julien ULiege; Cerfontaine, Vincent; Poelman, Dirk et al

Poster (2018, November)

In this work, TiO2 prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea ... [more ▼]

In this work, TiO2 prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea, ethylenediamine and triethylamine. Different molar N/Ti ratios are tested and the synthesis is adapted for each dopant. For urea- and trimethylamine-doped samples, anatase-brookite TiO2 nanoparticles of 6–8 nm are formed, with a specific surface area between 200 and 275 m2 g−1. In ethylenediamine-doped samples, the formation of rutile phase is observed, and TiO2 nanoparticles of 6–8 nm with a specific surface area between 185 and 240 m2 g−1 are obtained. X-ray photoelectron spectroscopy (XPS) and diffuse reflectance measurements show the incorporation of nitrogen in TiO2 materials through Ti–O–N bonds allowing light absorption in the visible region. Photocatalytic tests on the remediation of water polluted with p-nitrophenol show a marked improvement for all doped catalysts under visible light. The optimum doping, taking into account cost, activity and ease of synthesis, is up-scaled to a volume of 5 L and compared to commercial Degussa P25 material. This up-scaled sample shows similar properties compared to the lab-scale sample, i.e., a photoactivity 4 times higher than commercial P25. [less ▲]

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See detailSpray-coating as a scalable means for making TiO2 thin films in the context of advanced oxidative processes
Wolfs, Cédric ULiege; Mahy, Julien ULiege; Mertes, Alexander ULiege et al

Conference (2018, October 29)

Micropollutants are introduced into the environment by domestic, industrial or hospital waste waters. TiO2 photocatalysis is an efficient and versatile way of removal of these micropollutants. However ... [more ▼]

Micropollutants are introduced into the environment by domestic, industrial or hospital waste waters. TiO2 photocatalysis is an efficient and versatile way of removal of these micropollutants. However, efficient, low-cost production of TiO2 thin films is not straightforward in the case of big reactors. Spray-coating is presented as the better solution cost-wise, and as a similar solution efficiency-wise. [less ▲]

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