Electrospun polymer fibers containing poly(methyl methacrylate) (PMMA), Ti(OH)4, and UiO-66 convert a chemical warfare agent simulant to non-toxic product via catalytic hydrolysis.

PEDOT infused TiO2nanofibers exhibit enhanced photocatalytic performance by improved hole transfer for the degradation of PAP.

TiO2 polycrystalline sub-micron fibers can be used as photocatalysts for the degradation of a variety of organic molecules. Here we report on the optimization of these fibers for decontaminating pharmaceutical agents in aqueous medical waste streams. Mixed-phase TiO2 fibers have been prepared via a sol-gel technique followed by electrospinning and calcination. By adjusting the calcination temperature, the rutile phase fraction in TiO2 fibers can be tuned relative to the anatase phase from 0% to 100%. The effect of rutile phase fraction on grain size and specific surface area as well as their subsequent influences on the photocatalytic activity was investigated. An optimal grain size in post-calcined TiO2 fibers was found to be critical to balance the e(-)/h(+) volume recombination, surface recombination rate, and charge diffusion rate. The photocatalytic activities of the post-calcined TiO2 fibers with different rutile fractions were measured by monitoring the decreasing concentration of phenazopyridine in aqueous solution under UV illumination using UV-vis absorption spectroscopy. Post-calcined TiO2 fibers composing of 38 wt% rutile and 62 wt% anatase exhibited the highest initial degradation rate constant of 0.044 min(-1). This optimal photocatalytic activity can be attributed to the combined influences of the fibers' phase composition, surface area and grain size. (C) 2016 Elsevier B.V. All rights reserved.

There has been increased interest in titanium dioxide (TiO2) fibers as a photocatalyst for the degradation of persistent organic and biopharmaceutical toxins in the environment. The photocatalytic efficiency of TiO2 fibers is typically limited to UV irradiation due to its semiconductor bandgap. TiO2 fibers have been prepared and adsorbed the visible photosensitizer cis-dichlorobis(2,2'-bipyridyl-4,4'-dicarboxylic acid) ruthenium (II) (Ru(dcbpyH(2))(2)Cl-2) on the surface in order to absorb from 300 to 800 nm in the visible spectrum and drive photocatalysis. This dye fiber material has been applied to the degradation of 2,6-pyridinediamine,3-(phenylazo) monohydrochloride or phenazopyridine (PAP) as a model biopharmaceutical waste. The Ru(dcbpyH(2))(2)Cl-2-sensitized fibers degrade PAP under UV and visible irradiation following a first order reaction rate. The rate constants for PAP degradation in visible light when using bare TiO2 fibers and dye-sensitized TiO2 fibers were 0.014 +/- 0.001 min(-1) and 0.012 +/- 0.001 min(-1) respectively, showing little change. Under UV irradiation, the rate decreased from 0.032 +/- 0.003 min(-1) and 0.012 +/- 0.002 min(-1). These results suggest that the major pathway for the degradation of PAP may occur through the valence band. (C) 2016 Elsevier B.V. All rights reserved.

Nanocomposites of gold nanoparticles (AuNPs) embedded in polyaniline fibers have been fabricated using a one-pot synthesis approach and in-situ polymerization. By using a combination of inorganic acids (e.g. HCl) and camphorsulfonic acid, polyaniline nanostructured fibers of high aspect ratio with diameters of 150 ± 50 nm and several micrometers in length were obtained. These fibers afforded high electrical conductivity of 4.2 ± 0.5 S/cm. Encapsulation of the AuNPs in the polyaniline fibers afforded nanocomposites with high electrical conductivity and dielectric constant of 34.0 ± 0.5 S/cm and 65.3 ± 5 respectively. The morphology of these materials was analyzed using SEM and HRTEM and electronic properties were analyzed using UV-Vis spectroscopy.