Thermally oxidized iron oxide nanoarchitectures for hydrogen production by solar-induced water splitting

详细信息	查看全文 | 推荐本文 |

• 作者：Tracey Vincent ; Moran Gross ; Hen Dotan ; Avner Rothschild ; ^{avnerrot@technion.ac.il}
• 关键词：Water splitting ; Iron oxide ; 伪-Fe2O3 ; Hematite ; Nanowires ; Oxidation
• 刊名：International Journal of Hydrogen Energy
• 出版年：2012
• 期刊代码：42_03603199
• 类别：ch
• 出版时间：May, 2012
• 卷：37
• 期：9
• 页码：8102-8109
• 文件大小：1761 K

摘要

Thermally oxidized iron oxide (伪-Fe₂O₃, Hematite) nanostructures are investigated as photoanodes that convert solar energy into hydrogen by splitting water. 伪-Fe₂O₃ is stable for water photo-oxidation, it has a favorable band gap energy and is a non-toxic common material. However, 伪-Fe₂O₃ photoanodes suffer from high loss due to electron-hole recombination; therefore nanoarchitectures with high aspect ratio that allows photons to be absorbed close to the photoanode/electrolyte interface are preferred. The thermal oxidation of iron is a simple way to produce nanostructured iron oxide electrodes. Different morphologies, aspect ratios, and oxide thicknesses result depending on the process parameters. Nanorod structures were obtained by annealing iron foils in oxygen rich atmosphere, whereas annealing in oxygen lean atmosphere resulted in nanocoral-like morphology. The nanorod-structured photoanodes achieved moderate photocurrent density of 0.9聽mA/cm² while the nanocoral morphology achieved 2.6聽mA/cm² (both at 1.8聽V vs. the reversible hydrogen electrode). The effect of the oxidation process and oxide layer on performance is discussed.