WO3-Fe2O3 Photoanodes for Water Splitting: A Host Scaffold, Guest Absorber Approach
WO3-Fe2O3 Photoanodes for Water Splitting: A Host Scaffold, Guest Absorber Approach
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DOI：
10.1021/cm900565a
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发表时间：
2009-07-14
影响因子：
8.6
通讯作者：
Graetzel, Michael
中科院分区：
文献类型：
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作者：
Sivula, Kevin;Le Formal, Florian;Graetzel, Michael
通过用赤铁矿（Fe 2 O3）分解水的太阳能制氢受到弱光吸收和小空穴扩散长度的限制。这些缺点可以通过使用高表面积的主机，以支持一个薄层的赤铁矿，允许光生空穴产生在高度接近的光电流液体交界处克服。在这里，我们证明了这一概念的有效性，使用纳米结构的主机支架（WO 3）制备的大气压CVD支持一个薄层的Fe 2 O3纳米粒子沉积通过类似的方法。在主-客体电极中观察到光电流增加20%，与具有相同量的赤铁矿的对照膜（相当于60 nm膜）相比，在没有主支架的情况下沉积。这种改善归因于吸收光子转换效率（APCE）的增加。特别是对于光子在赤铁矿中穿透深度大的较长波长。对于波长为565 nm的光，APCE提高到8.0%，与对照膜的5.7%相比，因为主体/客体结构。
Solar hydrogen production via watersplitting with hematite (Fe2O3) has been limited by poor light absorption and a small hole diffusion length. These drawbacks can be overcome by using a high-surface-area host to support a thin layer of hematite-allowing photogenerated holes to be produced in high proximity to the semiconductor-liquid junction. Here we demonstrate the effectiveness of this concept using a nanostructured host scaffold (WO3) prepared by atmospheric pressure CVD to support a thin layer of Fe2O3 nanoparticles deposited by a similar method. A 20% increase in the photocurrent was observed in host-guest electrodes as compared to control films with the same amount of hematite (equivalent to a 60 nm film) deposited without the host scaffold. The improvement is attributed to an increase in the absorbed photon conversion efficiency (APCE). especially,for longer wavelengths where the photon penetration depth is large in hematite. For light with a wavelength of 565 nm, the APCE improves to 8.0%, as compared to 5.7% with the control films because of the host/guest architecture.