Coupling of piezoelectric, semiconducting and photoexcitation properties in NaNbO3 nanostructures for controlling electrical transport: Realizing an efficient piezo-photoanode and piezo-photocatalyst
Coupling of piezoelectric, semiconducting and photoexcitation properties in NaNbO3 nanostructures for controlling electrical transport: Realizing an efficient piezo-photoanode and piezo-photocatalyst
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DOI：
10.1016/j.nanoen.2017.05.029
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发表时间：
2017-08-01
期刊：
影响因子：
17.6
通讯作者：
Khare, Neeraj
中科院分区：
文献类型：
--
作者：
Singh, Simrjit;Khare, Neeraj
在半导体如ZnO和BaTiO 3中的压光电效应已经被较早地研究，但是这些各自材料的化学不稳定性和绝缘性质使它们不适合光电化学（PEC）和光催化应用。在这里，我们证明了一个有效的耦合之间的压电，半导体和光激发性能的化学稳定的NaNbO 3半导体，目的是提高效率的PEC水分解和光催化活性。我们表明，交替内置电位可以在周期性的机械应变下产生的光生电荷载流子的电荷分离的改善在NaNbO 3纳米结构。NaNbO 3颗粒悬浮液显示出大的（类似于115%）的增强，在工业废水中的有机染料的光降解率，这是远远高于早期报道的压电光催化活性在ZnO。对于PEC水裂解活性，NaNbO 3纳米结构薄膜沉积到柔性ITO涂层聚对苯二甲酸乙二醇酯（ITO/PET）基板上的极化通过施加外部电场。在压电辅助下，光电流密度从0.78 mA/cm（2）增加到1.02 mA/cm（2），入射光子到电流的转换效率提高了8%。我们目前的工作表明，在NaNbO 3的机械，光学和电学性能之间的有效耦合，因此，它可以被用作压电光电应用的潜在替代材料。
Piezophototronic effect in semiconductors such as ZnO and BaTiO3 has been studied earlier but chemical instability and insulating nature of these respective materials make them unsuitable for photoelectrochemical (PEC) and photocatalytic applications. Herein, we demonstrate an efficient coupling between piezoelectric, semiconducting and photoexcitation properties in chemically stable NaNbO3 semiconductor with an aim to enhance the efficiency of PEC water splitting and photocatalytic activities. We show that an alternating built-in potential can be generated in NaNbO3 nanostructures under periodic mechanical strain resulting in improved charge separation of the photogenerated charge carriers. NaNbO3 particulate suspension shows a large (similar to 115%) enhancement in the photodegradation rate of organic dyes in industrial waste water which is much higher than the earlier reported piezophotocatalytic activity in ZnO. For PEC water splitting activity, NaNbO3 nanostructure films deposited onto flexible ITO coated polyethylene terephthalate (ITO/PET) substrates were polarized by applying an external electric field. Enhancement in the photocurrent density from 0.78 mA/cm(2) to 1.02 mA/cm(2) and similar to 8% improvement in the incident photon to current conversion efficiency have been noted under the piezoassistance. Our present work demonstrates an efficient coupling between mechanical, optical and electrical properties in NaNbO3 thus, it can be used as a potential alternative material for piezophototronic applications.