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1,2,3-Triazole, a five-membered heterocyclic nucleus, is widely recognized as a key chromophore of great value in medicinal chemistry for delivering compounds possessing innumerable biological activities, including antimicrobial, antitubercular, antidiabetic, antiviral, antitumor, antioxidants, and anti-inflammatory activities. Mainly, in the past years, diverse conjugates carrying this biologically valuable core have been reported due to their attractive fungicidal potential and potent effects on various infective targets. Hence, hybridization of 1,2,3-triazole with other antimicrobial pharmacophores appears to be a judicious strategy to develop new effective anti-fungal candidates to combat the emergence of drug-sensitive and drug-resistant infectious diseases. Thus, the current review highlights the recent advances of this promising category of 1,2,3-triazole-containing hybrids incorporating diverse varieties of bioactive heterocycles such as conozole, coumarin, imidazole, benzimidazole, pyrazole, indole, oxindole, chromene, pyrane, quinazoline, chalcone, isoflavone, carbohydrates, and amides. It underlies their inhibition behavior against a wide array of infectious fungal species during 2015-2020.

Background: Infectious diseases still affect large populations causing significant morbidity and mortality. Bacterial and fungal infections for centuries were the main factors of death and disability of millions of humans. Despite the progress in the control of infectious diseases, the appearance of resistance of microbes to existing drugs creates the need for the development of new effective antimicrobial agents. In an attempt to improve the antibacterial activity of previously synthesized compounds modifications to their structures were performed. Methods: Nineteen thiazolidinone derivatives with 6-Cl, 4-OMe, 6-CN, 6-adamantan, 4-Me, 6-adamantan substituents at benzothiazole ring were synthesized and evaluated against panel of four bacterial strains S. aureus, L. monocytogenes, E. coli and S. typhimirium and three resistant strains MRSA, E. coli and P. aeruginosa in order to improve activity of previously evaluated 6-OCF3-benzothiazole-based thiazolidinones. The evaluation of minimum inhibitory and minimum bactericidal concentration was determined by microdilution method. As reference compounds ampicillin and streptomycin were used. Results: All compounds showed antibacterial activity with MIC in range of 0.12–0.75 mg/mL and MBC at 0.25–&gt, 1.00 mg/mL The most active compound among all tested appeared to be compound 18, with MIC at 0.10 mg/mL and MBC at 0.12 mg/mL against P. aeruginosa. as well as against resistant strain P. aeruginosa with MIC at 0.06 mg/mL and MBC at 0.12 mg/mL almost equipotent with streptomycin and better than ampicillin. Docking studies predicted that the inhibition of LD-carboxypeptidase is probably the possible mechanism of antibacterial activity of tested compounds. Conclusion: The best improvement of antibacterial activity after modifications was achieved by replacement of 6-OCF3 substituent in benzothiazole moiety by 6-Cl against S. aureus, MRSA and resistant strain of E. coli by 2.5 folds, while against L. monocytogenes and S. typhimirium from 4 to 5 folds.

Penicillin G is an old and widely used antibiotic. Its persistence in the environment started to appear in many environmental samples and food chains. The removal of these emerging pollutants has been a challenging task for scientists in the last decades. The photocatalytic properties of Cd2+ doped Manganese- Zinc NSFs with chemical formula (Mn0.5Zn0.5)[CdxFe2−x]O4 (0.0 ≤ x ≤ 0.05) NSFs are herein evaluated. The Manganese- Zinc N.S.F.s nanomaterials were deeply characterized, utilizing UV-Vis (reflectance) spectroscopy, X-ray diffraction, N2 adsorption isotherm measurements, and S.E.M., SEM-EDX mapping, and T.E.M. The Kinetic model for the photodegradation of penicillin G (as a model molecule) is investigated using visible light as a source of energy. The kinetic study shows that our results fit well with the modified pseudo-first-order model. The Pen G degradation are 88.73%, 66.65%, 44.70%, 37.62% and 24.68% for x = 0.5, 0.4, 0.3, 0.2 and 0.1, respectively, against 14.68% for the free Cd spinel sample. The pseudo-rate constant is bandgap dependent. From the intra-diffusion rate constant (Kd), we developed an intra-diffusion time (τ) model, which decreases exponentially as a function of (x) and mainly shows the existence of three different domains versus cadmium coordination in spinel ferrite samples. Hence, Cadmium’s presence generates spontaneous polarization with a strong opportunity to monitor the charge separation and then open the route to a new generation of “assisted” photocatalysts under visible light.

Background: Inflammation is a complex response to noxious stimuli promoted by the release of chemical mediators from the damaged cells. Metabolic products of arachidonic acid, produced by the action of cyclooxygenase and lipoxygenase, play important roles in this process. Several non-steroidal anti-inflammatory drugs act as cyclooxygenase inhibitors. However, almost all of them have undesired side effects. Methods: Prediction of the anti-inflammatory action of the compounds was performed using PASS Program. The anti-inflammatory activity was evaluated by the carrageenan paw edema test. COX and LOX inhibitory actions were tested using ovine COX-1, human recombinant COX-2 and soybean LOX-1, respectively. Docking analysis was performed using Autodock. Results: All designed derivatives had good prediction results according to PASS and were synthesized and experimentally evaluated. The compounds exhibited in vivo anti-inflammatory action with eleven being equal or better than indomethacin. Although, some of them had no or low inhibitory effect on COX-1/2 or LOX, certain compounds exhibited COX-1 inhibition much higher than naproxen and COX-2 inhibition, well explained by Docking analysis. Conclusions: A number of compounds with good anti-inflammatory action were obtained. Although, some exhibited remarkable COX inhibitory action this activity did not follow the anti-inflammatory results, indicating the implication of other mechanisms.

Graphene oxide (GO)-based nanocomposites have received a great attention due to their emerging applications. Here, we thoroughly examined the structural, electronic and surface properties of $$\hbox {GO}/\hbox {TiO}_{2}$$ nanotubes nanocomposite. The nanocomposite is prepared by simple impregnation of $$\hbox {TiO}_{2}$$ nanotubes (HNT400) with GO dispersion. GO is elaborated by an improved Hummer’s method, while HNT400 is obtained using alkaline hydrothermal treatment of $$\hbox {TiO}_{2}$$ P25, followed by calcination at $$400^{\circ }\hbox {C}$$ . XRD and Raman analyses show that GO nanosheets do not change the structural properties of $$\hbox {TiO}_{2}$$ nanotubes. TEM analysis confirms the formation of GO nanosheets assembled to $$\hbox {TiO}_{2}$$ nanotubes. XPS and EPR results confirm the electron transfer between GO and $$\hbox {TiO}_{2}$$ nanotubes. PL analysis reveals that GO inhibits the recombination of photogenerated electron–hole pairs in the nanocomposite. The ac conductivity measurements suggest the presence of grain and grain boundary effects in GO/HNT400.

SSCI-VIDE+CARE:ECI2D+MHM:GBE:FDA:CGU:HKO; International audience; The influence of polyhydroxyfullerene (PHF) on the photocatalytic properties of calcined hydrogenotitanate nanotubes (HNT) were evaluated in the present study. PHF-HNT nanocomposites were first characterized by N-2 adsorption-desorption measurements, X-ray diffraction, X-ray photoelectron, electron paramagnetic resonance and UV vis diffuse reflectance spectroscopies, transmission electron microscopy, photoluminescence, and photocurrent experiments. Correlation was then established with the photocatalytic properties of PHF-HNT nanocomposites during the photodegradation of formic acid. (C) 2017 Elsevier B.V. All rights reserved.

This paper builds on previous literature showing the interesting adsorptive properties of TiO2 nanotubes. It further explores the positive effect of β-cyclodextrin on these properties. Hence, β-cyclodextrin modified TiO2 nanotubes were successfully prepared and characterized by XRD, N2 physisorption at 77 K, Raman, FTIR-ATR, 1H NMR, TEM and EPR. The adsorptive interaction of Cu(II) with materials was investigated in aqueous solution at pH 9.25 (NH4+/NH3). The main conclusion is that copper(II)-ammonia complexation equilibria play an important role in the adsorption process. The β-cyclodextrin was found to improve the Cu(NH3)42+ adsorption mainly by retarding its precipitation to high concentrations values (>400 mg L−1). Adsorption experimental data showed good fit with the pseudo-second-order model and the Langmuir isotherm model.

SSCI-VIDE+CARE:ECI2D+MHM:FDA:CGU:GBE; International audience; 1D nanotubular TiO2 are known to improve photocatalytic performance compared to classical 3D particles. Combination of TiO2 nanotubes (NTs) with graphene oxide (GO) was previously envisaged to limit the recombination of e--h+ pairs (Appl. Cat. B 2017, 209, 203-213). Compared to non-reduced GO, improvement in activity was noticed if partially reduced GO was used due to a decrease in charge transfer resistance after partial reduction limiting the recombination phenomenon. If GO was totally reduced, the gain in activity was lost suggesting that the driving force for the injection of electrons from TiO2 to GO comes from the consumption of oxygen groups on graphene layers. The present study proposes an alternative for avoiding the consumption of photoelectrons through the addition of Cu NPs onto GO without contact with TiO2 NTs. Such a building is facilitated by the tendency of GO to wrap up around TiO2 NTs. Comparison was herein performed between Cu/TiO2 NTs and Cu/(R)GO/NTs systems. On Cu/TiO2 NTs, results show a stabilization of Cu NPs at a +I oxidation state due to a strong interaction with TiO2 NTs leading to a 80% increase in activity for formic acid (FA) degradation under UV. TiO2 NTs are also necessary in combination with Cu to acquire an enhanced photocatalytic response in the visible region or for the production of H2. Contrary to GO/TiO2 NTs, in the presence of Cu, addition of non-reduced GO leads to a 250% increase in activity compared to TiO2 NTs alone for FA photodegradation while the use of partially reduced GO leads to a similar photocatalytic response than with Cu/TiO2 NTs alone. This effect is due to a partial dislocation of the graphene layers wrapped around TiO2 NTs leading to a preferential relocation of Cu NPs directly onto TiO2 NTs.

Background: Inflammation is a complex response to noxious stimuli promoted by the release of chemical mediators from the damaged cells. Metabolic products of arachidonic acid, produced by the action of cyclooxygenase and lipoxygenase, play important roles in this process. Several non-steroidal anti-inflammatory drugs act as cyclooxygenase inhibitors. However, almost all of them have undesired side effects. Methods: Prediction of the anti-inflammatory action of the compounds was performed using PASS Program. The anti-inflammatory activity was evaluated by the carrageenan paw edema test. COX and LOX inhibitory actions were tested using ovine COX-1, human recombinant COX-2 and soybean LOX-1, respectively. Docking analysis was performed using Autodock. Results: All designed derivatives had good prediction results according to PASS and were synthesized and experimentally evaluated. The compounds exhibited in vivo anti-inflammatory action with eleven being equal or better than indomethacin. Although, some of them had no or low inhibitory effect on COX-1/2 or LOX, certain compounds exhibited COX-1 inhibition much higher than naproxen and COX-2 inhibition, well explained by Docking analysis. Conclusions: A number of compounds with good anti-inflammatory action were obtained. Although, some exhibited remarkable COX inhibitory action this activity did not follow the anti-inflammatory results, indicating the implication of other mechanisms.

GO-TiO 2 photocatalysts were prepared using titanium dioxide (TiO 2 ) samples obtained by physical mixing of different amounts of anatase and rutile. The anatase/rutile mixtures were then supported by graphene oxide (GO) or reduced graphene oxide (rGO). The photocatalytic activity of these materials was investigated in the photodegradation of formic acid as a model reaction under UV/A light irradiation. (r)GO-TiO 2 samples containing both anatase and rutile phases show higher activities than pure anatase, the maximum being reached with 88% anatase and 12% rutile. This synergism observed between anatase and rutile is amplified when graphene oxide is added, particularly under its reduced form. This enhancing effect was explained mainly in terms of electron transfer from anatase to rutile and then to graphene oxide or reduced graphene oxide. In this respect, partial reduction of graphene oxide appears as a remarkable way to avoid recombination of photogenerated electron-hole pairs. However, interestingly, the charge transfer is efficient only if rutile is present in TiO 2 samples.

SSCI-VIDE+CARE:ECI2D+MHM:GBE:CGU:HKO; International audience; The influence on the photocatalytic performance of TiO2 nanotubes (NT) resulting from the addition of graphene oxide (GO) was studied. TiO2 nanotubes (NT) were prepared using alkaline hydrothermal treatment of TiO2 P25 followed by calcination at 400 C under air. GO-NT composites were then obtained by wet impregnation of the as-prepared TiO2 nanotubes onto graphene oxide before reduction under H2 at 200 C. In a first step, the influence of the reduction treatment was evaluated on GO alone to determine its role towards the nature of the oxygen-containing functional groups present. GO-NT composites were also characterized considering both the effect of the reduction treatment and of the GO weight loading on textural, structural, electronic, and optical properties of TiO2 nanotubes. The resulting GO-NT composites were finally evaluated for the photocatalytic degradation of formic acid and compared to TiO2 nanotubes alone and to P25. Results emphasize a strong increase of the electron affinity and conductivity of the GO-NT composites if graphene oxide is reduced at 200 degrees C. These enhanced properties lead to an easier separation of photogenerated charges and to a limitation of the recombination of electron-hole pairs. A dramatic gain in photocatalytic response is observed. Maximum in photocatalytic efficiency is reached at a GO loading of 1.0 wt% while further increase of GO weight loading blocks light penetration and depletes the photocatalytic response. (C) 2017 Elsevier B.V. All rights reserved.

Selective adsorption of La, Ce, Y and Nd rare earth elements (REEs) from aqueous solution was performed using TiO2 nanotubes. Kinetic study reveals that REEs adsorption on TiO2 nanotubes is highly enhanced at pH 5 (acetate buffer). The experimental parameters keys such as pH, eluent concentration and flow rate are investigated. The desorption of REEs prior to ICP analysis is also studied. From thermodynamic study, the adsorption heats, are REEs atomic radius dependent, which opens a new route for the selective separation. An engineered packed column with TiO2 nanotubes was used under continuous flow for the REEs extraction. Our method yields excellent recovery (> 98%) of REEs, and the column can be regenerated up to 20 cycles.

An interesting adsorption capacity for TiO2 nanotubes has been demonstrated in this work using penicillin G (PEG), as the antibiotic model. Isotherms and kinetic studies revealed that PEG adsorptio...

AIR:EAU:RAFFINAGE:MATERIAUX+ATR:HKO:CGU:GBE; The influence of the sodium content on thermal stability and photocatalytic activity of calcined titanate nanotubes (TNT) was herein evaluated by preparing different samples through hydrothermal treatment of TiO2 powder (P25) in a concentrated NaOH solution (11.25 M) at 130 degrees C during 20 h followed by acid washing steps. Titanate nanotubes samples with sodium (Na-TNT) and sodium-free (H-TNT) were then obtained using different concentrations of HCI aqueous solutions namely 0.1 M and 1 M respectively. As synthesized nanomaterials with different Na percentages were then calcined at temperatures varying between 400 degrees C and 700 degrees C. Samples were characterized by means of nitrogen adsorption-desorption isotherms at 77 K, thermal analysis (DTA, TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and diffuse reflectance spectroscopy (DRS). The photocatalytic activities of Na-TNT and H-TNT derived nanomaterials were then evaluated through the photocatalytic degradation of formic acid (FA). Results show that the presence of sodium retards the dehydration process during the transformation of titanate into TiO2 shifting the formation of anatase phase to higher temperatures. However, sodium is not necessary to preserve the nanotubular morphology. The presence of sodium after calcination strongly impacts negatively the photocatalytic properties. If sodium is completely removed from the initial titanate orthorhombic phase, calcination leads to TiO2 anatase materials with enhanced photocatalytic properties compared to P25 in the degradation of formic acid, particularly if nanotubular morphology is preserved. The highest activity was therefore achieved for the H-TNT sample calcined at 400 degrees C. The photodegradation activity of formic acid depends on the specific surface areas and TiO2 crystallinity. In pure anatase nanoparticles the activity strongly decreases with coherent crystallographic domains >= 10 nm. (c) 2013 Elsevier B.V. All rights reserved.

SSCI-VIDE+CARE:ECI2D+MME:ATR:HKO:CGU:GBE; International audience; The influence of lanthanum on the thermal stability and photocatalytic activity of calcined hydrogenotitanate nanotubes (HNT) was hereinevaluated. HNT samples were prepared through the hydrothermal treatmentof TiO2 P25 in a concentrated NaOH solution (11.25 M) at 130 degrees Cduring 20 h followed by acid washing. La-doped titanates nanotubes(La-HNT) photocatalysts with optimum 1 wt% of La were then elaborated byincipient wetness impregnation method using lanthanum nitrate asprecursor. La HNT and HNT samples were then calcined at temperaturesvarying between 400 degrees C and 700 degrees C. Samples werecharacterized by means of nitrogen adsorption-desorption isotherms at77K, X-ray diffraction (XRD), Raman spectroscopy, diffuse reflectancespectroscopy (DRS), photoluminescence spectroscopy (PL), transmissionelectron microscopy (TEM), ICP analysis and photocurrent experiments.The photocatalytic activities of La-HNT and HNT derived nanomaterialswere then evaluated through the photocatalytic degradation of formicacid (FA).Main results reveal that lanthanum inhibits TiO2 crystallite growthand retards anatase transformation into the less active rutile phase.The addition of La ions to TiO2 results in a charge imbalance creating ahigh proportion of oxygen vacancies as evidenced by photocurrent,photoluminescence and Raman experiments.The photocatalytic experiments reveal that La-doped TiO2 helps tomaintain a high photocatalytic activity level even after calcination athigh temperatures contrary to La-free photocatalysts. The determinationof kinetic parameters reveals that the maintaining of a highphotocatalytic activity results from the synergetic effect betweenrestriction of TiO2 crystallite size growth and formation of a highproportion of oxygen vacancies.

SSCI-VIDE+ECI2D+GBE:HKO:GAN; International audience; Gold nanoparticles (NPs) with dendritic morphology were synthesized by a "green" seed-mediated approach in the presence of beta-cyclodextrin (beta-CD) as stabilizing biocompatible capping agent. First, 50 mL of an aqueous solution containing 5 mM of beta-CD were prepared, to which a variable amount of HAuCl4 was added. The beta-CD/Au molar ratio was monitored from 20 to 200. Optical properties, including Surface-Enhanced Raman Scattering (SERS) activity, of the synthesized structures were characterized by Raman and UV-vis spectroscopies. Morphology was studied by transmission electron microscopy (TEM). Samples prepared using this procedure presents an increase of their SERS signal with respect to samples without peak-rich morphology. Optimized nanodendrites were obtained at a beta-CD/Au molar ratio of 100. Moreover, a growth mechanism is proposed to describe the beta-cyclodextrin role in the synthesis of Au nanodendrites. The "green" seed-mediated synthesis technique used herein produces Au NPs with good biocompatibility pointing them out for biomedical applications.

Titanium dioxide nanotubes were prepared via a hydrothermal treatment of TiO 2 powder (Degussa P25). Obtained samples were analyzed by various techniques, such as transmission electron microscopy (TEM) and X-ray diffraction (XRD), which revealed that the crystal structure of the obtained materials was similar to that of H 2 Ti 2 O 5 ·H 2 O nanotubes, and were about 50 nm in length and 20 nm in diameter. Nitrogen adsorption–desorption isotherms indicated that synthesized solids are mesoporous materials with a multi-walled nanotubular structure and high specific surface area. The methanol oxidation reaction was investigated on platinum nanoparticles supported TiO 2 nanotubes (XC72). The electrocatalytic activity of the catalyst was measured by cyclic voltammetry. CO stripping voltammetry in acidic solutions was investigated to study the reaction of the catalysts towards poisoning by carbonyl compounds. The results demonstrated that Pt/TiO 2 nanotubes catalyst exhibits the best activity for methanol oxidation and were favorable for improving the tolerance to poisoning species.

Mesostructured TiO2 nanomaterials with tuned crystallite sizes were elaborated by a novel green route using soluble starch as the structuring agent and titanium(IV) isopropoxide as the inorganic pr...

Bimetallic Au–Pd clusters were successfully elaborated by selective deposition over citrate-functionalized TiO2 nanocrystallites. Anisotropic gold nanoparticles are obtained by adjusting the Pd/Au ...

Nanostructured palladium particles (nanorods, icosahedra, cubes) were synthesized in aqueous solution using a seeding-mediated approach with a structure-directing agent. These nanostructured Pd particles were then impregnated onto hydrogenotitanate nanotubes using two different impregnation procedures. The as-prepared catalysts were then tested in the selective hydrogenation of cinnamaldehyde at 323 K under 10 bars of H2. The selectivity is influenced by the morphology of the Pd nanostructured particles with a higher selectivity into saturated alcohols when the proportion of (111) Pd sites increases.

International audience; A novel and easy synthesis route to mesoporous nanocrystalline TiO2 samples using soluble starch as the structural agent and mainly titanium(IV) isopropoxide as the inorganic precursor was described. The effect of key parameters, including soluble starch removal process, the solvent nature and the type of titanium precursor were discussed. Using soluble starch in cyclohexane as non polar solvent, a surface area of 94 m2.g−1 associated with 23 nm crystallites size was obtained. TiO2 samples were characterized by means of N2 adsorption-desorption, X-ray Diffraction (XRD), TG-DTA, Scanning Electron Microscopy (SEM) and ATR-FTIR spectroscopy.

[EN] One-pot deposition of Au onto TiO2 has been achieved through directly contacting gold (III) salt with nanosized functionalized TiO2 support initially obtained by sol-gel process using titanium isopropoxide and citric acid. Citrate groups act as functional moieties able to directly reduce the Au salt avoiding any further reducing treatment. Various gold salts (NaAuCl4 center dot 2H(2)O or HAuCl4 center dot 3H(2)O) and titanium to citrate (Ti/Cit) molar ratios (20, 50 and 100) were used in order to study the effect of the nature of the precursor and of the citrate content on the final Au particle size and catalytic properties of the as-obtained Au/TiO2 materials. Au/(TiO2)(x)(Cit)(1) catalysts characterization was performed using N-2 adsorption-desorption, ICP-AES, X-ray diffraction and TEM. The effect of the Ti/Cit molar ratio and of the gold precursor was evaluated. The selective oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) was studied as a model reaction. Kinetic analysis showed that the catalytic reaction rate was pseudo first-order and the values of activation energy have been reported. Results showed that the functionalization of TiO2 by citrate allows tuning the size of the Au nanoparticles deposited onto TiO2 as well as their morphology. Citrate also strongly enhances the benzyl alcohol oxidation through the control of the size and morphology of gold nanoparticles. (C) 2014 Elsevier B.V. All rights reserved., This work has been supported by the Instituto de Tecnologia Quimica (UPV-CSIC), Universidad Politecnica de Valencia-Consejo Superior de Investigaciones Cientificas, project number A/020411/08 et du Ministere Tunisien de l'Enseignement Superieur et de la Recherche Scientifique.

SSCI-VIDE+CARE:ECI2D+MME:HKO:GBE:CGU; International audience; In this work, the design of cerium doped TiO2 nanomaterials with tuned structural and textural properties is reported. The influence of the cerium content of doped TiO2 solids (x = 1 to 5 wt%) on the photocatalytic degradation of formic acid using UV-A light was evaluated.The best photocatalytic activity was reached for 1 wt% of cerium.The effect of post-thermal treatments was also herein highlighted by varying the calcination temperature between 400 degrees C and 700 degrees C for simultaneously doped- and cerium-free TiO2 samples. Characterization was performed by means of nitrogen adsorption-desorption isotherms at 77K, X-ray diffraction, Raman spectroscopy, Photoluminescence (PL) spectroscopy, and diffuse reflectance UV-vis spectroscopy. The presence of Ce limits the growth of TiO2 crystallite sizes during the post-thermal treatment and favors stabilization of the TiO2 anatase phase. The presence of cerium also increases the number of surface defects and transforms them to non-radiative centers able to capture the photogenerated electrons as observed by PL spectroscopy. This would leave photogenerated holes available improving consequentlythe photocatalytic activity for the oxidation of formic acid. Finally, a possible pathway mechanism is proposed to confirm the obtained results. (C) 2015 Published by Elsevier B.V.

SSCI-VIDE+CARE:ECI2D+MME:MHM:GBE:CGU:HKO; International audience; La-C-60/TiO2 nanocomposites were successfully obtained by dry impregnation method. The effect of La and polyhydroxylated fullerenolC-60(OH)n addition order onto TiO2 was carefully highlighted.Interesting photocatalytic activity was achieved for the materialfirstly added with lanthanum. The increase in photocatalytic activity isattributed mainly to the synergy between fullerenol and La. Fullerenolenhances the electron charge transfer; whereas La increases the TiO2thermal stability by adjusting the TiO2 crystallites sizes to low valuesand also by creating some structural defects.

SSCI-VIDE+CARE:ECI2D+MME:GBE:CGU:HKO; International audience; Lanthanum doped 1D-TiO(2)nanomaterials (nanorods and nanotubes) with tuned structural and textural properties have been evaluated in the photocatalytic degradation of formic acid (FA) under UV conditions. La-doped nanorods and nanotubes calcined at 973 K show interesting photocatalytic properties with respect to La-free nanomaterials. The presence of La inhibits TiO2 crystallite growth and increases the lifetime of photo-generated electron-hole pairs. (C) 2014 Elsevier B.V. All rights reserved.

A thioresistant NOx trap based on CuO supported on sulphated zirconia mixed with a solid base is described. The rate of adsorption of NO at constant temperature and the amount of NO retained from a feed containing 750 ppm NO, 10% O2 and 5% water in nitrogen were measured. On badly dispersed CuO, the capacity for NOx adsorption does not decrease but slightly increases in the presence of 25 ppm SO2 in the feed. By contrast, a well dispersed Cu catalyst is irreversibly poisoned. The surface nitrates can be decomposed in air at 623 K. In a mixture, Ar + 1% H2, the nitrate is partly reduced to N2 at about 630 K, even after operation in the presence of SO2. The catalyst does not lose adsorption capacity after 10 cycles of adsorption–desorption and can be used in the temperature range 473–773 K. The resistance to SO2 depends also in part of the properties of the solid base.

The isomerization of styrene oxide has been investigated on mixed oxides obtained by calcination of hydrotalcites, rare earth phosphates and KF supported on alumina. All solids form β-phenylacetaldehyde. Basic catalysts deactivate rapidly or show a lower selectivity, most probably due to the formation of heavy products by aldolisation. ZnAl catalyst shows a selectivity towards β-phenylacetaldehyde >98% with no deactivation after 7 h on stream, in a flow gas phase process at 423 K.

AIR:EAU:RAFFINAGE:MATERIAUX+ATR:CGU:FDA:GBE:HKO; 1D-TiO2 nanomaterials (nanotubes, nanorods, nanoplates, nanospheres and nanoparticles) with tuned structural and textural properties have been evaluated in the photocatalytic degradation of formic acid (FA) under UV conditions. The FA adsorption isotherms follow the model of Langmuir and the kinetic of FA photodegradation shows Langmuir-Hinshelwood model whatever the TiO2 morphologies. TiO2 nanotubes (HTNT-400), nanoplates (HTNW-700) and nanoparticles (HTNT-500 and HTNT-600) show an interesting photocatalytic activities compared to TiO2 nanospheres (P25) and nanorods (TNR). The nanotubular TiO2 (HTNT-400) has a photocatalytic activity 4 times higher than TiO2 P25. The enhanced activity is attributed to the smaller crystallite size of anatase and tuned surface area of the photocatalyst. The pH study showed that the coexistence of HCOO- and HCOOH species at natural pH (ca. 3.5) is favourable for better adsorption on active sites of titanium oxide nanomaterials and consequently to a better photocatalytic activity. (C) 2014 Elsevier B.V. All rights reserved.

Oxidation of primary hydroxyl groups of potato starch to the corresponding carboxylic acids was performed in a fluidized bed using N2-diluted NO2 as oxidant. FT-IR spectrum of the oxidized starch show the presence of two absorption bands at 1743 and 1379 cm−1. The absorption at 1743 cm−1 which normally attributed to carbonyl absorption vanishes after washing the oxidized starch by water. Then two new absorption bands appeared at 1650 and 1400 cm−1 corresponding to the ionized carboxyl groups. The presence of nitrate favor the un-ionized form of carboxyl groups and then the band at 1743 cm−1 can be observed. Furthermore, the ionized carboxyl absorption (1600, 1400 cm−1) are replaced by carbonyl absorption at 1743 cm−1 by adding DCl. By means of 13C NMR analysis, oxidized starch, show a band around 200 ppm attributed to carboxylic acid, no formic acid was detected indicating that no cleavage took place under the applied reactions conditions.

Primary hydroxyl groups were oxidized regioselectively to carboxylic acid using organic nitrosonium salts generated on supported silver catalysts, which promote disproportionation of 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) in aqueous solution. The oxidation reactions were performed at pH 9.5 in a batch reactor at room temperture using heterogeneous silver catalysts and peroxides as primary co-oxidants; e.g., 99 mol% selectivity to methyl-α-D-glucopyrasiduronic acid was obtained at 90% conversion of the pyranoside using a silver carbonate–celite catalyst . The efficiency of the system was increased by adding carbonates to the silver catalyst. This result is explained by the increase of the electron charge deficiency on silver in the presence of carbonate, which accelerates the nucleophilic attack of hydroxyls and/or TEMPO. In the case of the Ag–Al2O3 catalyst, this result was proved by temperature-programmed desorption measurements using ammonia. With primary/secondary polyols, the selectivity for the primary hydroxyl groups is high. In addition, primary hydroxyl groups, as in the case of pyranosides, were oxidized more selectively than those of the furanosides. The observed regioselectivity is due to the sterical hindrance caused by the four methyl groups in TEMPO.

Hydrophobic mesoporous titano-silicates (HyMTS) have been prepared at ambient temperature by a sol–gel technique using hexadecyl-trimethyl-ammonium chloride in acid medium as templating surfactant. The gellation time increases for low reaction temperatures and low H + /Si ratios. The amorphous materials thus obtained at long gellation times show hydrophobic properties and a lower number of OH bearing Si atoms as determined from 29 Si MAS NMR. In the epoxidation of norbornene with H 2 O 2 or of cyclohexene with tert-butyl hydroperoxide, HyMTS reaches selectivities for the epoxide of 95% or higher. The epoxidation of cyclohexene by H 2 O 2 also gives better selectivities to the epoxide on these hydrophobic samples, compared to hydrophilic solids. It is suggested that hydrophobicity results from the slow kinetics of gellation.

AIR:EAU:RAFFINAGE:MATERIAUX+HKO:CGU:GBE; Photocatalysis is a well known efficient process for the decontamination of wastewaters pollutants. In the last decade an intense research was focused on the elaboration of well tuned TiO2 photocatalysts with the basic idea to understand the relationship between exposed facet and reactivity. In this work, four TiO2 morphologies are examined namely: nanotubes (NT), nanoplates (NPL), nanorods (NR) and nanospheres (NS). The solar photocatalytic properties are compared in the disinfection of a Fusarium solani inoculated solution. Disinfection using the solar light has been studied and the effect of formic acid (FA) was examined. We demonstrated, for the first time, that the solar inactivation of the resistant spores of Fusarium in water is related to the exposed TiO2 facets. At very low concentration of photocatalyst, the inactivation of F. solani over TiO2 nanospheres shows the best disinfection efficiency with respect to the others morphologies. Experiments on simultaneous photocatalytic decontamination of FA and inactivation of F. solani showed that the presence of FA strongly retards the disinfection reaction in the case of TiO2 nanospheres while the FA degradation occurred simultaneously with F. solani inactivation in the case of TiO2 NT. This result shows the interest of TiO2 NT for the decontamination and disinfection of wastewaters containing acidic pollutants and pathogens. (C) 2012 Elsevier B.V. All rights reserved.

Shape-controlled Ag and Pd nanocrystals were synthesized using seed-mediated techniques using β-cyclodextrin (β-CD) as structuring agent. First, seeds were obtained by reacting Na2PdCl4 or AgNO3 with a strong reducing agent, NaBH4 in the presence of sodium citrate dihydrate acting as stabilizing agent. These seeds were then injected into a growth solution containing the same metallic precursor, ascorbic acid (as a weak reducing agent) and β-CD as structuring agent. TEM results emphasize a strong influence of the relative concentration of β-CD on the final morphology. In the case of silver, well-facetted nanocrystals were obtained with a progressive shift from kinetically to thermodynamically-controlled nanoobjects when increasing the β-CD/Ag molar ratio. On palladium, β-CD leads to the formation of dendrites (urchin-like) or multipods through controlled aggregation of primary particles. The use of β-CD does not interfere negatively with the catalytic properties of the Pd nanocrystals in the hydrogenation of cinnamaldehyde.

1 D TiO2 nanomaterials (nanotubes, nanowires) were synthesized through hydrothermal treatment of TiO2 powder (P25) in concentrated alkaline solutions (NaOH for nanotubes, KOH for nanowires) followed by calcination at varying temperatures between 400°C and 700°C. Samples were characterized by HRTEM, XRD, Raman spectroscopy, and N2 adsorption-desorption isotherms. High surface area nanotubular TiO2 materials can maintain their 1D morphology up to a temperature of calcination of 400°C while changing their phase from hydrogenotitanate to anatase. The use of KOH leads to a retarded formation of anatase. Photocatalytic results showed that TiO2 anatase nanotubes calcined at 400°C can degrade formic acid with a rate constant four times higher than for P25. A direct correlation between surface area and photocatalytic activity explains the much higher activity of TiO2 anatase nanotubes. On the opposite, for the degradation of phenol, P25 remains more active. In the disinfection of water, contrary to P25, the high surface area of TiO2 nanotubes allows the simultaneous degradation of formic acid and the inactivation of pathogen fungus showing the interest of such materials for the treatment of wastewater.

EAU:RAFFINAGE:MATERIAUX+AME:HKO:SDA:VME:GBE; One-pot deposition of Pd onto TiO2 has been achieved through directly contacting palladium(II) salt with nanosized functionalized TiO2 support initially obtained by 501-gel process using titanium isopropoxide and citric acid. Citrate groups act as functional moieties able to directly reduce the Pd salt avoiding any further reducing treatment. Various palladium salts (Na2PdCl4 and Pd(NH3)(4)Cl-2 center dot H2O center dot H2O) and titanium to citrate (Ti/CA) ratios (20, 50, and 100) were used in order to study the effect of the nature of the precursor and of the citrate content on the final Pd particle size and catalytic properties of the as-obtained Pd/TiO2 systems. Characterization was performed using N-2 adsorption-desorption isotherms, ICP-AES, FTIR, XRD, XPS, and TEM. The as-obtained hybrid Pd/TiO2 catalysts were tested in the selective hydrogenation (HYD) of an m,alpha beta-unsaturated aldehyde, i.e. cinnamaldehyde. Citrate-free Pd/TiO2-based catalysts present lower selectivity into saturated alcohol. However, citrate-functionalized Pd/TiO2 catalyst seems to control the selectivity, the particle size and dispersion of Pd NPs leading to high intrinsic activity. (C) 2011 Elsevier Inc. All rights reserved.

An analytical method based on TiO2 nanotubes solid-phase extraction (SPE) combined with gas chromatography (GC) was established for the analysis of seven polycyclic aromatic hydrocarbons (PAHs): acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors affecting the extraction efficiency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01-0.8 microg/mL, repeatability of the extraction (RSD were between 6.7% and 13.5%, n = 5) and satisfactory detection limits (0.017-0.059 ng/mL). The developed method was successfully applied to the analysis of surface water (tap, river and dam) samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.