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The photoreduction of adsorbed copper ions onto Au nanoparticles, on an indium tin oxide (ITO) electrode in an aqueous electrochemical cell, is studied as a function of applied voltage and laser intensity. The numerical simulation of the Butler-Volmer kinetic equation has predicted several orders of magnitude increase in current for a temperature rise of a few Kelvin, which is sufficient to cause measurable difference in the surface properties of gold nanoparticles and facilitate the deposition of copper.

The temperature-dependent Raman spectroscopy technique is employed to study the crystal structure, as well as the paraelectric-to-ferroelectric phase transition of nanoscale barium titanate (BaTi[O.sub.3]). The phase transition is shown to be diffuse in temperature for the smaller particles.

Preparation of graphite carbon sheets and tubes from solution at temperatures as low as 110 degree centigrade is reported. The kinetic control and direction of the process is anticipated once the catalytic centers are fully characterized at low temperatures although the present reaction is not selective with respect to which form the graphite is produced.

We have investigated the paraelectric-to-ferroelectric phase transition of various sizes of nanocrystalline barium titanate (BaTiO3) by using temperature-dependent Raman spectroscopy and powder X-ray diffraction (XRD). Synchrotron X-ray scattering has been used to elucidate the room temperature structures of particles of different sizes by using both Rietveld refinement and pair distribution function (PDF) analysis. We observe the ferroelectric tetragonal phase even for the smallest particles at 26 nm. By using temperature-dependent Raman spectroscopy and XRD, we find that the phase transition is diffuse in temperature for the smaller particles, in contrast to the sharp transition that is found for the bulk sample. However, the actual transition temperature is almost unchanged. Rietveld and PDF analyses suggest increased distortions with decreasing particle size, albeit in conjunction with a tendency to a cubic average structure. These results suggest that although structural distortions are robust to changes in particle size, what is affected is the coherency of the distortions, which is decreased in the smaller particles. [ABSTRACT FROM AUTHOR]