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TiO 2 nanoparticle-based dye-sensitized solar cells (DSSCs) were modified by depositing a layer of a long-persistent phosphor, SrAl 2 O 4 :Eu 2+ ,Dy 3+ , on top of the TiO 2 nanoparticle layer to prepare working electrodes of the DSSCs. SrAl 2 O 4 :Eu 2+ ,Dy 3+ red-shifted the short UV wavelengths into the main absorption range of the dye commonly used in DSSCs. The SrAl 2 O 4 :Eu 2+ ,Dy 3+ layer also acted as a light-scattering layer to reduce the loss of visible light. Incident photon to current conversion efficiency measurements showed that the application of such phosphor materials enhanced light-harvesting. The open-circuit voltage was found to be higher in the modified DSSCs. The electrons produced by the SrAl 2 O 4 :Eu 2+ ,Dy 3+ particles contribute to the reduction of I 3 − to I − , leading to a lower I 3 − concentration in the electrolyte. This reduces the recapture of electrons injected in the conduction band of TiO 2 by triiodide ions and promotes the open circuit voltage. The performance of the modified DSSC device was improved compared with the cell using a working electrode without this phosphor layer. An overall 13% improvement in conversion efficiency of modified DSSCs was achieved due to the presence of the phosphor layer.

Ultrafine PEG-capped gadolinium oxide NPs doped with erbium ions, which could serve as a dual-imaging agent for MRI/optical imaging were synthesized using a simple, green, and quick method.

Increased demand of environment protection encouraged scientists to design products and processes that minimize the use and generation of hazardous substances. This work presents comprehensive result of large-scale fabrication and investigation of red-to-green tunable submicron spherical yttria particles codoped with low concentrations of Eu(+3) and Tb(+3). The color emission of synthesized particles can be precisely tuned from red to green by simple variation of Tb/Eu ratio and excitation wavelength. The Tb/Eu-codoped Y(2)O(3) particles did not adversely affect the viability of L-929 fibroblastic cells at concentrations less than 62.5 ppm. Through internalization and wide distribution inside the cells, Tb/Eu codoped Y(2)O(3) particles with intense bright green or red fluorescence rendered cell imaging to be possible. The high brightness, excellent stability, low-toxicity, and imaging capability along with fine color-tunability of synthesized particles enable to find promising application in various areas.

Rare-earth phosphors are commonly used in display panels, security printing, and fluorescent lamps, and have potential applications in lasers and bioimaging. In the present study, Eu3+- and Dy3+-codoped uniform-shaped Y2O3 submicron particles were prepared using the urea homogeneous precipitation method. The structure and morphology of the resulting particles were characterized by X-ray diffraction, field emission scanning electron microscope, and field emission transmission electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The room-temperature luminescence color emission of the synthesized particles can be tuned from red to yellow by switching the excitation wavelength from 254 to 350 nm. The luminescence intensities of red and yellow emissions could be altered by varying the dopant concentration. Strong quenching was observed at high Eu3+ and Dy3+ concentrations in the Y2O3 host lattice.

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Multifunctional mesoporous silica nanocomposites are attractive carriers for targeted drug delivery in nanomedicine. Although promising developments have been made in the fabrication of multifunctional mesoporous silica nanocomposites, the design and mass production of novel multifunctional carriers are still challenging. This paper reports the facile one-pot fabrication of a multifunctional inorganic composite composed of superparamagnetic Fe3O4 nanoparticles and coated dye-functionalized mesoporous silica with a high specific surface area. The resulting composite particles had a tunable particle size, special open pore channels with high specific surface area, which is quite favorable for drug loading and release properties, as well as luminescent and superparamagnetic properties suitable for targeted drug delivery and tracking. This composite exhibited low toxicity, suggesting potential biomedical applications.

The adsorption of N 2 on the open-ended single-walled carbon nanotube bundles was studied. The amount corresponding to the first coverage adsorbed on open-ended carbon nanotube bundles is three times larger than the amount adsorbed on closed-ended nanotube bundles. The isosteric heat of adsorption was obtained from the adsorption isotherm measurement performed at temperatures ranging from 117 to 130 K. The estimated heat of adsorption of nitrogen on the open-ended nanotube bundles is about twice as great as that on the closed-ended nanotube bundles. This leads directly to the conclusion that the binding energy of nitrogen on the open-ended nanotube is greater than that of nitrogen on the closed-ended nanotube bundles.