Autori: Sabina Grigorescu, Chong-Yong Lee, Kiyoung Lee, Sergiu Albu, Indhumati Paramasivam, Ioana Demetrescu, Patrik SchmukiT
Editorial: Electrochem Communications, Vol. 23, , p.59-62, 2012.
Different iron oxide structures were formed by annealing of iron foils in air at temperatures between 500 °C to 800 °C. Depending on temperature, a significant variation in the hematite/magnetite ratio and a strongly temperature dependent morphology is obtained. While over a wide range of conditions more or less compact Fe3O4/Fe2O3 layers are obtained, at 600 °C rapid growth (several micrometer per hour) of highly crystalline hematite nanowires can be observed. Visible light photocurrent measurements in 1 M NaOH under AM 1.5 100 mW/cm2 conditions show that photocurrent density and the onset potential for water oxidation strongly shifted in the cathodic direction for the nanowire morphology. The results indicate that a simple air oxidation of iron can provide a rapid path to form hematite nanowires. Obtained layers are considerably active as photoanodes for solar water splitting.
Cuvinte cheie: oxid fier, descompunerea apei, fotoanod // Iron oxide; Thermal annealing; Water splitting; Photoanode