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In a context of volatile organic compound photodecomposition, we have addressed TiO2-based macroscoscpic fiber generation. We have extruded hybrid sols of amorphous titania nanoparticles, latex nanoparticles, and nonionic surfactant (Tergitol) as structure-directing agents into a poly(vinyl alcohol) (PVA) solution bearing salts acting as a flocculating medium. The resulting nanocomposite TiO2/latex/PVA macroscopic fibers were thermally treated in air to open porosity by organic removal while generating the photocatalytically active anatase phase of TiO2along with residual brookite. Considering the synthetic paths, we have varied both the diameter of the latex particles as well as their concentration within the starting sol. These parameters allow tuning both the voids created through the applied thermal treatment and the fiber final diameters. For gas-phase photocatalysis, we have shown that the fiber diameters, mesoscopic roughness, and macroscopic topological defects represent indeed important morphological parameters acting cooperatively toward both acetone degradation and its mineralization processes. Particularly, triggering the fiber morphological characteristics, we have increased their efficiency toward acetone degradation of around 550% when compared with previous work.

Composite PVA/ZnO‐nanorods fibers, synthesized through co‐axial flux extrusion exhibit higher anisotropic photonic properties, both in absorption and emission, as a result of the collective alignment of the ZnO nanorods along the main axis of the PVA fiber. This photonic anisotropy is triggered by a synergistic interaction between the PVA matrix, stretched above the glass transition temperature (Tg), and cooled down under strain. Compared with non‐elongated fibers that present an isotropic emission, composite fibers previously submitted to a tensile stress absorb selectively UV emission when the polarized laser beam is parallel to the main axis of the fiber. In addition, their photolumincescence is also anisotropic, with a waveguide behavior along the main axis of the fiber. Mechanical properties of these composite fibers are also drastically improved, compared with pure PVA fibers: the longitudinal Young modulus of these fibers is increased from 2 to 6 GPa upon ZnO addition, a value similar to those already observed for composite fibers, prepared either with carbon nanotubes, or V2O5macroscopic fibers.

Three-dimensional connected Pd nanowires forming nanoballs have been synthesized by slow reduction of Pd IIin hexagonal mesophases made by a quaternary system (water/cyclohexane/surfactant/cosurfactant). Both confinement and slow reduction are necessary to obtain these new nanostructures. This material exhibits remarkable electrocatalytic behavior for ethanol oxidation in 1 M KOH and appears as a promising candidate for use in direct ethanol fuel cells.

Submicrometric hollow spheres with mesoporous walls were prepared by applying the synthesis of MSU-X type mesoporous silica at neutral pH. The application of ultrasound in the proper power range, to a mixture of nonionic polyoxyethylene surfactant and unreacted silicon alkoxide (tetraethylorthosilicate) gives a stable emulsion where the cavitation bubbles created by the ultrasound are trapped in the solution. Further hydrolysis and condensation of the silica by the addition of sodium fluoride freezes the structure and gives a powder that exhibits a single reflection in the X-ray diffraction pattern, characteristic of a 3D-wormhole ordered porous framework. Its main feature is a large hysteresis loop in the nitrogen adsorption/desorption isotherm. This hysteresis loop corresponds to the retention of condensed nitrogen within the voids of these particles that can play the role of tanks for volatile compounds.

Phosphorus-31 NMR and Raman analyses have been performed in order to check the stability of the hexathiodiphosphate(IV) anion [P2S6]4– in aqueous solutions. This anion appears to be better stabilized in basic media than in acidic ones. Moreover, a gentle oxidation by a diluted solution of hydrogen peroxide allowed a partial substitution of sulfur by oxygen atoms that leads to mono- and di-substituted anions, respectively, [P2S5O]4– and [P2S4O2]4–, with a total yield of 72% conversion, compared with the initial hexathiodiphosphate anion.

Nichtionische Polyethylenoxid‐Detergentiensind vielseitige strukturdirigierende Agentien bei Synthesen mesoporöser Molekularsiebe. Ihr größter Nutzen könnte darin bestehen, daß sie zu mesoporösen Strukturen führen, deren Porengröße von der Synthesetemperatur abhängt. Für mesoporöse Silicate mit wurmlochartigen Strukturmotiven kann der durchschnittliche Porendurchmesser Rdurch Variation der Synthesetemperatur in einem engen Bereich unterhalb des Trübungspunktes des Detergens um bis zu 2.4 nm verändert werden; eine typische Größenverteilung ist rechts oben gezeigt.

We present a Nb K-edge EXAFS study of carbon- and alumina-supported niobium sulfide hydrotreatment catalysts. NbS2 and NbS3 entities have been evidenced on the carbon support, and NbS2 and Nb1−yS ones on the alumina support. EXAFS spectra of carbon-supported species, which are highly disordered, were analyzed through an asymmetric distance distribution model. Considering their poor dispersion, Nb1−yS species can be thought to be intrinsically highly active. Their activity, and that of NbS3 entities as well, can possibly be related to cation clustering. Niobium sulfides appear as very sensitive to support effects.

An aluminium phenylphosphonate, Al(OH)(O₃PC₆H₅), has been studied. Its poor long-range crystallographic organisation required the use of local probe techniques such as 31P and 27Al MAS NMR and XAS. An unexpectedly narrow and symmetric 27Al MAS NMR signal was obtained, with an isotropic chemical shift that has not been observed earlier in aluminium phosphonates. XANES and EXAFS studies showed unambiguously that this signal had to be attributed to a five-fold coordination site, the first observed for a phosphonato-aluminium atom.

Nonionic polyethylene oxide surfactantsare versatile structure-directing agents for the assembly of mesoporous molecular sieves, but their greatest benefit may lie in their ability to control the pore size of the mesostructure by the assembly temperature (see dependence of pore diameter Ron temperature shown on the right). For mesostructured silicas with wormhole motifs, the average pore diameter can be altered by as much as 2.4 nm by varying the assembly temperature over a relatively narrow range below the cloud point temperature of the surfactant.

Spherical particles of mesoporous MSU-X silica in the micrometric size range have been obtained through a new double step process that led to an easy and highly reproducible synthesis pathway giving micelle templated structures with a large surface area and narrow pore size distribution

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