سال انتشار: ۱۳۹۱
محل انتشار: اولین همایش ملی حفاظت و برنامه ریزی محیط زیست
تعداد صفحات: ۶
Kourosh Motevalli – Instructor, Applied Chemistry Department, Fundamental Sciences Faculty, Islamic Azad University
Zahra Yaghoubi – Assistant Professor, Industrial Faculty, Islamic Azad University, South Tehran Branch, Tehran, Iran,
The photoelectrolysis of water to yield hydrogen and oxygen using visible light has enormous potential for solar energy harvesting if suitable photoelectrode materials can be developed. Few ofthe materials with a band gap suitable for visible light activation have the necessary band edge potentials or photochemical stability to be suitable candidates. Osmium oxide )Ebg =2.8 eV( is a good candidate with absorption up to λ ≈ ۴۴۰ nm and known photochemical stability. Thin filmsof osmium oxide were prepared using an electrolytic route from peroxoosmium precursors. Theosmium oxide thin films were characterised by FESEM, Auger electron spectroscopy, and photoelectrochemical methods. The magnitude of the photocurrent response of the films under solar simulated irradiation showed a dependence on precursor used in the film preparation, with a comparatively lower response for samples containing impurities. The photocurrent response spectrum of the osmium oxide films was more favourable than that recorded for titanium dioxide )TiO2 ( thin films. The OsO3 photocurrent response was of equivalent magnitude but shifted intothe visible region of the spectrum, as compared to that of the TiO2 .