Ni-Doped Overlayer Hematite Nanotube: A Highly Photoactive Architecture for Utilization of Visible Light

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• 作者：Weiren Cheng ; Jingfu He ; Zhihu Sun ; Yanhua Peng ; Tao Yao ; Qinghua Liu ; Yong Jiang ; Fengchun Hu ; Zhi Xie ; Bo He ; Shiqiang Wei
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：November 15, 2012
• 年：2012
• 卷：116
• 期：45
• 页码：24060-24067
• 全文大小：464K
• 年卷期：v.116,no.45(November 15, 2012)
• ISSN：1932-7455

文摘

To efficiently transform absorbed photons to chemical energy is highly desired for the full utilization of visible light in solar hydrogen generation process. Here, a highly active photoanode consisting of a thin Ni_xFe_2鈥?i>xO₃ overlayer on the surface of hematite nanotube has been constructed to raise the utilization of the photoexcited carriers by Fe₂O₃ in the visible spectrum. We find that the obtained overlayer photoanodes promote the charge migration of photogenerated carriers to the surface, accelerating surface oxygen evolution and avoiding low-energy photoexcited holes recombination at the semiconductor鈥搇iquid junction. Relative to the pristine Fe₂O₃ photoanodes, a sustainably high incident photon to electron conversion efficiency from 40% at 400 nm until 10% at 500 nm is observed for Ni-doped overlayer hematite, yielding 280% enhancement of the photoconversion efficiency. Our results provide some guidance for the future design and optimization for the structure of photoanode.