Toward the Intrinsic Superiority of Aligned One‐Dimensional TiO 2 Nanostructures: the Role of Defect States in Electron Transport Process
Toward the Intrinsic Superiority of Aligned One‐Dimensional TiO 2 Nanostructures: the Role of Defect States in Electron Transport Process
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DOI：
10.1002/celc.202001127
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
Zhijuan He;Yanyang Han;Shanshan Liu;W. Cui;Yunping Qiao;Tao He;Qianxi Wang
中科院分区：
文献类型：
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作者：
Zhijuan He;Yanyang Han;Shanshan Liu;W. Cui;Yunping Qiao;Tao He;Qianxi Wang
由排列的1D半导体纳米结构制成的电极在光电化学应用中引起了广泛的关注，因为它们被期望是用于将电子引导向衬底而没有横向电子散射的理想配置。然而，几乎没有努力优化这种系统中的缺陷状态。在此，我们观察到显着的增强（20倍）的光电化学性能的二氧化钛纳米棒阵列（NRA）后，一个简单的煅烧过程。 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：即使在由1D TiO 2纳米棒组成的电极中，也可以避免横向电子散射，这通过测量无陷阱电子扩散系数（D0）得到证实，电子传输过程可以受到分布在带隙中的缺陷态的严重影响。煅烧过程可以优化TiO2 NRA的结构，从而促进电子传输过程。本质上，这项工作提供了一个结构视图，为实现上级性能的对齐的一维半导体纳米结构。
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 TiO2nanorod 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 TiO2nanorods, 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 TiO2NRAs, therefore facilitates electron transport process. Intrinsically, this work provides a structural view for realizing the superior performance of aligned 1D semiconductor nanostructures.