Electrodes made up of aligned 1D semiconductor nanostructures have drawn much attention in photoelectrochemical applications, as they are expected to be ideal configuration for channeling electrons towards the substrate without lateral electron scattering. However, efforts were hardly made to optimize the defect states in such systems. Herein, we observed significant enhancement (∼20 fold) in photoelectrochemical performance of TiO₂ nanorod arrays (NRAs) after a simple calcination procedure. Through a series of structural and electrochemical characterizations, we revealed an underlying role of defects states in electron transport: even in electrodes composed of 1D TiO₂ nanorods, lateral electron scattering would be avoided, which was confirmed by measuring the trap‐free electron diffusion coefficient (D₀), the electron transport process can be severely affected by defect states distributed in the band gap. The calcination procedure can bring structural optimization for TiO₂ NRAs, therefore facilitates electron transport process. Intrinsically, this work provides a structural view for realizing the superior performance of aligned 1D semiconductor nanostructures.

中文翻译：

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取向一维TiO2纳米结构的内在优势：缺陷态在电子传输过程中的作用

由对齐的一维半导体纳米结构组成的电极在光电化学应用中备受关注，因为它们被认为是将电子引导至衬底而不会发生横向电子散射的理想配置。但是，在这种系统中几乎没有努力优化缺陷状态。在这里，我们观察到经过简单的煅烧程序后，TiO ₂纳米棒阵列（NRAs）的光电化学性能有了显着提高（约20倍）。通过一系列的结构和电化学表征，我们揭示了缺陷态在电子传输中的潜在作用：甚至在由一维TiO ₂组成的电极中通过测量纳米棒，可以避免横向电子散射，这可以通过测量无陷阱电子扩散系数（D ₀）来确认，电子传输过程会受到带隙中分布的缺陷态的严重影响。煅烧过程可以为TiO ₂ NRAs带来结构优化，从而促进电子传输过程。本质上，这项工作为实现对准的一维半导体纳米结构的卓越性能提供了结构视图。