Ni-Doped Overlayer Hematite Nanotube: A Highly Photoactive Architecture for Utilization of Visible Light
Ni-Doped Overlayer Hematite Nanotube: A Highly Photoactive Architecture for Utilization of Visible Light
复制标题
掺杂镍覆盖层赤铁矿纳米管：一种利用可见光的高光敏结构
DOI：
10.1021/jp306738e
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发表时间：
2012-11-15
影响因子：
3.7
通讯作者：
Wei, Shiqiang
中科院分区：
文献类型：
--
作者：
Cheng, Weiren;He, Jingfu;Wei, Shiqiang
为了在太阳能制氢过程中充分利用可见光，迫切需要将吸收的光子有效地转化为化学能。本文在赤铁矿纳米管表面构建了一层薄薄的NixFe2-xO3包覆层组成的高活性光阳极，以提高Fe2O3在可见光光谱中的光激发载流子利用率。我们发现所获得的光阳极层促进了光生载流子向表面的电荷迁移，加速了表面氧的析出，并避免了半导体-液体结处低能光激发空穴的复合。相对于原始的Fe2O3光阳极，ni掺杂的赤铁矿层的入射光子到电子的转换效率从400nm的40%持续到500nm的10%，光转换效率提高了280%。我们的研究结果对未来光阳极结构的设计和优化具有一定的指导意义。
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 NixFe2-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-liquid 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 similar to 280% enhancement of the photoconversion efficiency. Our results provide some guidance for the future design and optimization for the structure of photoanode.