Comparative impedance spectroscopy study of rutile and anatase TiO₂ film electrodes

The purpose of this work was a comparative electrochemical impedance analysis of the titanium dioxide-solution interface for two kinds of thin film samples consisting respectively of anatase and rutile. These kind of films, frequently used in photoelectrochemical experiments, have recently been the subject of detailed physical studies showing important differences in electrical properties between those two forms of TiO2. The EIS measurements were carried out over a wide frequency range (from 0.03 Hz to 10 kHz), analysing the whole spectrum

Investigation of nanocrystalline TiO₂ films by means of impedance spectroscopy

Thin film electrodes consisting of a TiO2 powder nanodispersed on different substrates, displaying unusual photoelectrochemical properties have been investigated using EIS method. It was established, that for non-illuminated electrodes, the EIS spectra are characteristic of the substrate; the poorly doped nanodispersed powder is virtually not observed being shunted by parallelly connected substrate capacitance. In contrast, classical sol/gel anatase electrodes yield linear Mott-Shottky plots characteristic of their active layer.</p

Synthesis and Electrocatalytical Application of Hybrid Pd/Metal Oxides/MWCNTs

The performance of Pd electrocatalysts for formic acid electrooxidation was improved by application of metal oxide-multiwall carbon nanotubes composites as a catalyst support. Hybrid oxides/MWCNTs were synthesized by two different methods: chemical reduction method and impregnation method. Pd based catalysts were synthesized by polyol method on the MWCNTs or oxide/MWCNTs composites. The In2O3 was deposited on MWCNTs by impregnation method (In2O3/MWCNTs-IM support) and in the presence of NaBH4 (In2O3/MWCNTs-NaBH4 support). The physical properties of the Pd/In2O3/MWCNTs-IM, Pd/In2O3/MWCNTs-NaBH4, Pd/SnO2/MWCNTs, and Pd/MWCNTs catalysts were characterized and their electrocatalytical performance in formic acid oxidation was compared. During Pd deposition on In2O3/MWCNTs-NaBH4 support, InPd2 structure was formed as observed by XRD. The electrochemical tests indicate that the two Pd/ In2O3/MWCNTs electrocatalysts have higher electrocatalytic activity than those of Pd/SnO2/MWCNTs and Pd/MWCNTs. The best performance was observed for the catalyst obtained by In2O3 impregnation of MWCNTs denoted by Pd/In2O3/MWCNTs-IM