Ru/CdS Quantum Dots Templated on Clay Nanotubes as Visible-Light-Active Photocatalysts: Optimization of S/Cd Ratio and Ru Content.

A nanoarchitectural approach based on in situ formation of quantum dots (QDs) within/outside clay nanotubes was developed. Efficient and stable photocatalysts active under visible light were achieved with ruthenium-doped cadmium sulfide QDs templated on the surface of azine-modified halloysite nanotubes. The catalytic activity was tested in the hydrogen evolution reaction in aqueous electrolyte solutions under visible light.

Study of Nanostructured TiO₂ Rutile with Hierarchical 3D-Architecture. Effect of the Synthesis and Calcinations Temperature.

The effect of TiCl₄ hydrolysis temperature on the structural, textural and morphological properties of the resulting rutile and on the changes of these properties upon calcination was studied. The XRD, Raman spectroscopy, mercury porosimetry, BET, SEM and TEM studies have revealed that TiO₂ rutile has a hierarchical 3D-architecture. The obtained nanostructured rutile had a cauliflowerlike/ spherical morphology composed of fan-shaped nanofibers.

Synthesis of CdZnS photocatalysts for gas-phase CO reduction under visible light.

Novel photocatalysts for CO2 reduction, which consist of a cadmium and zinc sulfide solid solution (Cd1-xZnxS), were successfully prepared by a simple two-step technique. The photocatalysts were characterized by X-ray diffraction, UV-VIS diffuse reflectance spectroscopy, and low-temperature N2 adsorption techniques and were tested in the gas-phase photocatalytic reduction of CO2 under visible light (λ = 450 nm). All the synthesized Cd1-xZnxS solid solutions were capable of enabling the chemical transformations of CO2 under the conditions considered.

Low power upconversion using MLCT sensitizers.

Selective low energy excitation of the metal-to-ligand charge transfer (MLCT) transition in [Ru(dmb)(3)](2+)(dmb = 4,4'-dimethyl-2,2'-bipyridine) in the presence of anthracene or 9,10-diphenylanthracene yields easily visualized upconverted singlet fluorescence resulting from triplet-triplet annihilation at low excitation power.

Synthesis and properties of novel fluorescent switches.

[reaction: see text] Photochromic dithienylethene moieties were covalently attached to fluorescent 4,4-difluoro-8-(4'-iodophenyl)-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (iodo-BODIPY) via a phenylacetylene linker. UV light induced isomerization of the photochrome results in significant decrease in fluorescence intensity. This fluorescence can be recovered with visible light.

Anti-Stokes delayed fluorescence from metal-organic bichromophores.

Long wavelength excitation of [Ru(dmb)(2)(bpy-An)](2+) (dmb is 4,4'-dimethyl-2,2'-bipyridine and bpy-An is 4-methyl-4'-(9-anthrylethyl)-2,2'-bipyridine) in CH(3)CN solution produces upconverted delayed singlet anthracene fluorescence via bimolecular triplet-triplet annihilation.

Room temperature phosphorescence from ruthenium(II) complexes bearing conjugated pyrenylethynylene subunits.

We describe the synthesis, electrochemistry, and photophysical properties of several Ru(II) complexes bearing different numbers of pyrenylethynylene substituents in either the 5- or 5,5'-positions of 2,2'-bipyridine, along with the appropriate Ru(II) model complexes bearing either bromo- or ethynyltoluene functionalities. In addition, we prepared and studied the photophysical behavior of the diimine ligands 5-pyrenylethynylene-2,2'-bipyridine and 5,5'-dipyrenylethynylene-2,2'-bipyridine. Static and dynamic absorption and luminescence measurements reveal the nature of the lowest excited states in each molecule.