Nanostructures of poly(2,2′:5′,2′′-terthiophene) have been synthesized using only electrochemical techniques. To this end, a porous silica film modified platinum disc was used as working electrode (Pt|(SiO2)n). The silica coating acts as a template so that the subsequent electro-polymerization occurs in their confined space pores, perpendicular to the electrodic surface. The current response of the obtained polymeric deposit is much greater than that exhibited by the solid massive polymer (generated under identical conditions but without template), accounting for the significant increase of the p-doping/undoping charge. Template removal was accomplished by treating the deposits with HF solutions. It was demonstrated that as the template is removed, the charge of the nanostructured electrodes increases even more. Electro-deposit characterization was supplemented using transmission electron microscopy, TEM, and FT-Raman spectroscopy, which revealed the obtaining of electrodes modified with polymeric nanostructures vertically aligned upon the electrode surface. Thus, a methodology employing solely electrochemical techniques that enables the obtainment of polymeric nanodeposits directly on the electrode surface was proposed. This approach allows foreseeing a significant progress in applications wherein these materials are useful, since this methodology, first tested for polythiophene, is applicable to various starting units capable of being electro-synthesized.
Dynamic structure factor of charge density was evaluated by MD simulation for molten LiI with artificially varied ionic masses. The dispersion curve was obtained from the peak frequency of collective excitation. The peak frequency at zero wavevector and the modulus of group velocity were estimated from the dispersion curves, as a function of ionic mass. The peak frequency at zero wavevector shows that the optic mode can be thermally excited for all the molten alkali halides. This suggests the ideas that the charge-density modes may dominate the thermal transport in these systems, and that insensitivity of the thermal conductivity of molten alkali halides to details of interionic potentials can be attributed to the behavior. The obtained modulus of group velocity was roughly proportional to mG−1/2, where mG is the geometric average of anion and cation masses. This suggests that it may partially replace the mass term in the expression of thermal conductivity.
We have constructed a sheet-type glucose/dioxygen enzymatic biofuel cell with multi-stacked structure, in which one biocathode is sandwiched with two bioanodes in parallel. The energy density of the biofuel cell reached 14.1 mWh cm−3. The cell has achieved the acceptable performance on re-fueling, and the stability of the cell before use was drastically improved by adding raffinose.
Phase-separating porous glass (PG) was studied with respect to the ion-exchange reaction of Cs+ ions from aqueous solutions, and the effect of residual sol (aluminosilicate, in particular) in the pores was examined. Cs+ uptake from solutions containing Cs+ ions only was excellent in both the presence and absence of aluminum. For solutions containing additional ions, selective adsorption of Cs+ was only observed when aluminum was present in the PG. The results show that Cs+ ion-exchange can be controlled by slight changes in the chemical composition of PG.
We fabricated dye-sensitized solar cells (DSSCs) with synthetic quartz nanoparticle (SQNP)-supported Pt/fluorine doped tin oxide counter electrodes to utilize an adsorptive capacity of synthetic quartz. The amperage of I3− reduction was 1.6 times higher with SQNP than that without SQNP. SQNP also improved the photocurrent density-voltage characteristics and the incident photon to current conversion efficiency spectra in the visible region. These suggest that SQNP enhances the I3− reduction activity on the counter electrode and the electron transfer to the photoanode. The SQNP-supported counter electrode is expected to be useful to raise the efficiency of a DSSC.