Si-doped Fe₂O₃ nanotubular/nanoporous layers for enhanced photoelectrochemical water splitting

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• 作者：Chong-Yong Lee ; Lei Wang ; Yuya Kado ; Robin Kirchgeorg ; Patrik Schmuki
• 关键词：Fe2O3 ; Si doping ; Water splitting ; Photoelectrochemistry
• 刊名：Electrochemistry Communications
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：34
• 期：Complete
• 页码：308-311
• 全文大小：695 K

文摘

The present work reports the enhancement of the photoelectrochemical water splitting performance of in-situ silicon (Si)-doped nanotubular/nanoporous (NT/NP) layers. These layers were grown by self-organizing anodization on Fe-Si alloys of various Si content. The incorporation of Si is found to retard the layer growth rates, leads to a more pronounced nanotubular morphology, and most importantly, an improved photoelectrochemical behavior. By increasing Si content from 1, 2 to 5 at. % in the iron oxide NT/NP photoanodes, the photocurrent onset potential shifts favorably to lower values. At 1.3 V vs. RHE, hematite layer with 5 at. % Si shows a 5-fold increase of the photocurrent, i.e. 0.5 mA cm^? 2 in comparison to 0.1 mA cm^? 2 for the undoped samples. The study also reveals that a suitable layer thickness is essential to achieve a beneficial effect of the Si doping.