Jong-Seong Bae

Electrochemical oxidation of some basic alcohols on multiwalled carbon nanotube–platinum composites

Some composites of multiwalled carbon nanotubes, which were chemically treated in acidic and/or hydrogen peroxide solution, and platinum nanoparticles were prepared by the simple reduction in glycerol solution. Carboxylated and/or hydroxyl MWNTs were structurally analysed using X-ray photoelectron spectroscopy. In addition, the MWNT–Pt composites were characterized by XRD and TEM in detail. The electrochemical oxidation of some basic alcohols, which was catalyzed by the MWNT–Pt composites, was analysed by cyclic voltammetry. Their catalytic activities were studied with cyclic voltammograms of alcohols.

Preparation and Characterization of CdSe-Decorated Multiwalled Carbon Nanotube Composites

Composites of carboxylated multiwalled carbon nanotubes (c-MWNTs) and CdSe nanoparticles were prepared by the electrostatic interaction. CdSe nanoparticles were stabilized by 2-(dimethylamino)ethanethiol hydrochloride to develop positive charges on their surfaces in aqueous solution. The structural characteristics of these composites were analyzed using X-ray diffraction (XRD), and transmission electron microscopy (TEM). Ultraviolet/visible (UV/vis) spectra of c-MWNT–CdSe composites showed the characteristic bands at ~250 nm. These results indicate that the energy state of c-MWNTs is significantly modified, which was caused by the homogeneous distribution of CdSe nanoparticles in c-MWNTs, and the bond formation between c-MWNTs and CdSe nanoparticles. The photoluminescence (PL) of CdSe nanoparticles in the composites was characterized in comparison with that of CdSe nanoparticles. PL of CdSe in c-MWNT–CdSe composites was collected at ~568 nm in solution, but disappeared in powder state.

Characteristics of SiO 2 /Si Quantum Dots Super Lattice Structure Prepared by Magnetron Co-Sputtering Method

Solar cells have been more intensely studied as part of the effort to find alternatives to fossil fuels as power sources. The progression of the first two generations of solar cells has seen a sacrifice of higher efficiency for more economic use of materials. The use of a single junction makes both these types of cells lose power in two major ways: by the non-absorption of incident light of energy below the band gap; and by the dissipation by heat loss of light energy in excess of the band gap. Therefore, multi junction solar cells have been proposed as a solution to this problem. However, the and generation solar cells have efficiency limits because a photon makes just one electron-hole pair. Fabrication of all-silicon tandem cells using an Si quantum dot superlattice structure (QD SLS) is one possible suggestion. In this study, an matrix system was investigated and analyzed for potential use as an all-silicon multi-junction solar cell. Si quantum dots with a super lattice structure (Si QD SLS) were prepared by alternating deposition of Si rich oxide (SRO; (x