Enhanced performance of dye-sensitized solar cells by utilization of an external, bifunctional layer consisting of uniform β-NaYF₄:Er³⁺/Yb³⁺ nanoplatelets.

Uniform β-NaYF(4):Er(3+)/Yb(3+) hexagonal nanoplatelets were synthesized via a modified hydrothermal route, and the nanoplatelets were applied as an external, bifunctional layer in a novel DSC configuration consisting of only one internal TiO(2) transparent layer. Approximately 10% enhancements of photocurrent and overall DSC efficiency are demonstrated by the addition of the external layer, which exhibits two functions of light reflecting and near-infrared (NIR) light harvesting. The novel DSC configuration not only simplifies the DSC fabrication process but also eliminates charge recombination induced by the conducting up-converting nanocrystals when used internally thus opening the path for other more efficient up-converting nanocrystals to be designed and applied.

Near-infrared sunlight harvesting in dye-sensitized solar cells via the insertion of an upconverter-TiO₂ nanocomposite layer.

Er(3+),Yb(3+) co-doped LaF₃-TiO₂ nanocomposites (UC-TiO₂) are inserted as a middle layer in a novel tri-layer photoanode design (see Figure) of a dye-sensitized solar cell (DSSC). The Er(3+),Yb(3+) co-doped LaF₃ part of the nanocomposite helps capture near-infrared (NIR) light by converting it into visible light absorbable by the dye hence opening the road for the development of DSSCs with higher conversion efficiency and photocurrent output.

The synthesis of aqueous-dispersible anatase TiO2 nanoplatelets.

Aqueous well-dispersed and phase-pure anatase TiO(2) truncated octahedron nanoplatelets (NPLs) were prepared via controlled hydrolysis of titanium tetrachloride (TiCl(4)) in ethylene glycol at 240 degrees C. Two shapes, square and hexagon, were observed by microscopy, exactly corresponding to the truncated octahedron NPLs. Ethylene glycol was found to produce water in situ that reacts with TiCl(4) to produce TiO(2) and HCl-the latter promoting TiO(2) colloid peptization.

Biodesulfurization of dibenzothiophene by microbial cells coated with magnetite nanoparticles.

Microbial cells of Pseudomonas delafieldii were coated with magnetic Fe3O4 nanoparticles and then immobilized by external application of a magnetic field. Magnetic Fe3O4 nanoparticles were synthesized by a coprecipitation method followed by modification with ammonium oleate. The surface-modified Fe3O4 nanoparticles were monodispersed in an aqueous solution and did not precipitate in over 18 months.

Immobilization of Pseudomonas delafieldii with magnetic polyvinyl alcohol beads and its application in biodesulfurization.

Pseudomonas delafieldii was immobilized in magnetic polyvinyl alcohol (PVA) beads using a hydrophilic magnetic fluid, which was prepared by a co-precipitation method. The beads had distinct super-paramagnetic properties and were compared with immobilized cells in non-magnetic PVA beads. Their desulfurizing activity was increased slightly from 8.