Designed synthesis of SiO2/TiO2 core/shell structure as light scattering material for highly efficient dye-sensitized solar cells.

SiO2/TiO2 core/shell nanoparticles (STCS-NPs) with diameters of 110, 240, and 530 nm were fabricated to investigate the influence of the size and refractive index of light-scattering particles on light-scattering properties. The optical properties of STCS-NPs were evaluated and compared with SiO2-NPs and TiO2-NPs. The structure of STCS-NPs, consisting of a low refractive index core and high refractive index shell, provides efficient light scattering. The optimized anode film with STCS-NPs had ca. 20% improved power conversion efficiency (PCE).

Designed architecture of multiscale porous TiO2 nanofibers for dye-sensitized solar cells photoanode.

Multiscale porous (MSP) TiO(2) nanofibers (NFs) were fabricated using a simple electrospinning and etching process with TiO(2)/SiO(2) composite NFs for high-efficiency dye-sensitized solar cells (DSSCs). TiO(2) NFs with different pore sizes (small, large, and multiscale) were prepared using SiO(2) nanoparticles of various sizes. The surface area of the MSP TiO(2) NFs was nine times higher than that of pristine TiO(2) NFs, providing sufficient dye adsorption for light harvesting as well as efficient paths for electrolyte contact. Moreover, the one-dimensional structure provides efficient light scattering and fast electron transport. As a result, DSSCs exhibited an enhanced current density (J(sc)) of 16.3 mA cm(-2) and a high photoconversion efficiency (η) of 8.5%, greater than those of conventional photoelectrodes made of TiO(2) nanoparticles (J(sc) of 12.0 mA cm(-2) and η of 6.0 %).

Controllable synthesis of highly conductive polyaniline coated silica nanoparticles using self-stabilized dispersion polymerization.

Highly conductive silica/polyaniline (PANi) core/shell nanoparticles (NPs) were synthesized in various diameters (from 18 to 130 nm) using self-stabilized dispersion polymerization. The polymerization was carried out in an aqueous/organic liquid system at -30 °C. In this system, the organic phase plays a key role in directing para-direction oriented polymerization of the PANi on the surface of silica NPs. Because of its para-direction polymerized structure, the synthesized silica/PANi core/shell NPs exhibited enhanced electrical conductivity (25.6 S cm(-1)) compared with NPs (1.4 S cm(-1)) prepared by homogeneous polymerization. The conductivities and BET surface areas were 25.6 S cm(-1)/170 m(2) g(-1) (18 nm in diameter), 22.5 S cm(-1)/111 m(2) g(-1) (35 nm in diameter), 18.3 S cm(-1)/78 m(2) g(-1) (63 nm in diameter), and 16.4 S cm(-1)/53 m(2) g(-1) (130 nm in diameter). In this series, increased para-coupling along the polymer backbone was elucidated using several characterization techniques, including Fourier transform infrared (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) spectroscopy. As-prepared silica/PANi core/shell NPs exhibited capacitance as high as 305 F g(-1).

Spatially controlled carbon sponge for targeting internalized radioactive materials in human body.

Carbon sponge, an adsorbent with spatially controlled structure is demonstrated for targeting internalized radiocesium and other radionuclides in human body. Three dimensionally ordered macroporous (3DOM) carbons derived from inverse opal replicas of colloidal-crystal template exhibit large surface area and high porosity, resulting in highly efficient adsorbents for radionuclides. It is also possible to enhance binding affinity and selectivity to radionuclide targets by decoration of 3DOM carbon surfaces with Prussian blue (PB) nanoparticles, and synthesized PB nanoparticles reveal low toxicity toward macrophage cells with potential advantages over oral administration. It is noteworthy that the maximum (133)Cs adsorption capacity of PB-decorated 3DOM carbons is 40.07 mmol g(-1) which is ca. 30 and 200 times higher than that of commercialized medicine Radiogardase(®) and bulk PB, respectively. Further, adsorption kinetics study indicates that the PB-decorated 3DOM carbons have the homogenous surface for (133)Cs ion adsorption and all sites have equal adsorption energies in terms of ion exchange between the cyano groups of the PB-decorated 3DOM carbons and radionuclides. As a concept of the oral-administrable "carbon sponge", the PB-decorated 3DOM carbons offer useful implications in the separation science of radioactive materials and important insight for designing novel materials for treatment of patients or suspected internal contamination with radioactive materials.