Photocatalytic generation of hydrogen by core-shell WO₃/BiVO₄ nanorods with ultimate water splitting efficiency.
Photocatalytic generation of hydrogen by core-shell WO₃/BiVO₄ nanorods with ultimate water splitting efficiency.
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DOI：
10.1038/srep11141
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发表时间：
2015-06-08
影响因子：
4.6
通讯作者：
Kitamori T
中科院分区：
文献类型：
--
作者：
Pihosh Y;Turkevych I;Mawatari K;Uemura J;Kazoe Y;Kosar S;Makita K;Sugaya T;Matsui T;Fujita D;Tosa M;Kondo M;Kitamori T
高效的光催化水分解需要光诱导载流子的有效产生、分离和转移，这在单一材料中很难同时实现。本文表明，在具有极薄吸收层的纳米异质结中，每个过程的效率可以分别最大化。我们在WO3/BiVO4+CoPi核壳纳米结构光阳极上证明了这一概念，并获得了接近理论的水分解效率。BiVO4的特点是光生成载流子的高复合率，其扩散长度远短于充分吸收光所需的厚度。这一问题可以通过将BiVO4与更具导电性的WO3纳米棒以核壳异质结的形式结合来解决，其中BiVO4吸收层比载流子扩散长度更薄，而其光学厚度则通过高纵横比纳米结构中的光捕获来重建。我们的光阳极在1个太阳照射下，在1.23 VRHE下显示出6.72 mA cm - 2的最终水分解光电流，相当于BiVO4理论可能值的~90%。我们还演示了光阳极与双结GaAs/InGaAsP光伏电池串联的自偏压操作，其稳定的水分解光电流为6.56 mA cm−2，对应于太阳能制氢效率为8.1%。
Efficient photocatalytic water splitting requires effective generation, separation and transfer of photo-induced charge carriers that can hardly be achieved simultaneously in a single material. Here we show that the effectiveness of each process can be separately maximized in a nanostructured heterojunction with extremely thin absorber layer. We demonstrate this concept on WO3/BiVO4+CoPi core-shell nanostructured photoanode that achieves near theoretical water splitting efficiency. BiVO4 is characterized by a high recombination rate of photogenerated carriers that have much shorter diffusion length than the thickness required for sufficient light absorption. This issue can be resolved by the combination of BiVO4 with more conductive WO3 nanorods in a form of core-shell heterojunction, where the BiVO4 absorber layer is thinner than the carrier diffusion length while it’s optical thickness is reestablished by light trapping in high aspect ratio nanostructures. Our photoanode demonstrates ultimate water splitting photocurrent of 6.72 mA cm−2 under 1 sun illumination at 1.23 VRHE that corresponds to ~90% of the theoretically possible value for BiVO4. We also demonstrate a self-biased operation of the photoanode in tandem with a double-junction GaAs/InGaAsP photovoltaic cell with stable water splitting photocurrent of 6.56 mA cm−2 that corresponds to the solar to hydrogen generation efficiency of 8.1%.
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影响因子：
16.6
作者：
Abdi, Fatwa F.;Han, Lihao;van de Krol, Roel
通讯作者：
van de Krol, Roel
影响因子：
32.5
作者：
Luo, Wenjun;Yang, Zaisan;Zou, Zhigang
通讯作者：
Zou, Zhigang
DOI：
10.1016/1010-6030(94)03777-9
发表时间：
1994-07-12
影响因子：
4.3
作者：
KATAKIS, D;MITSOPOULOU, C;VRACHNOU, E
通讯作者：
VRACHNOU, E
影响因子：
4.5
作者：
Abdi, Fatwa F.;Firet, Nienke;van de Krol, Roel
通讯作者：
van de Krol, Roel
影响因子：
--
作者：
Dall'Antonia, Luiz Henrique;de Tacconi, Norma R.;Rajeshwar, Krishnan
通讯作者：
Rajeshwar, Krishnan