Modification of 1D TiO2 nanowires with GaOxNy by atomic layer deposition for TiO2@GaOxNy core–shell nanowires with enhanced photoelectrochemical performance
Modification of 1D TiO2 nanowires with GaOxNy by atomic layer deposition for TiO2@GaOxNy core–shell nanowires with enhanced photoelectrochemical performance
复制标题
通过原子层沉积用 GaOxNy 修饰一维 TiO2 纳米线，获得具有增强光电化学性能的 TiO2@GaOxNy 核壳纳米线
DOI：
10.1039/c9nr10908k
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发表时间：
2020
期刊：
影响因子：
6.7
通讯作者：
David-Wei Zhang
中科院分区：
文献类型：
--
作者：
Jia-Jia Tao;Hong-Ping Ma;Kai-Ping Yuan;Yang Gu;Jian-Wei Lian;Xiao-Xi Li;Wei Huang;Michael Nolan;Hong-Liang Lu;David-Wei Zhang
TiO2作为一种众所周知的可以催化析氧反应的半导体，其太阳能光电化学水性质得到了广泛的研究。未经改性的TiO2表现出一些问题，特别是在光电化学性能方面。在本文中，我们提出了一种利用原子层沉积技术在TiO2 1D纳米线（TiO2@GaOxNy核壳）上沉积一定量的GaOxNy共催化剂的策略。我们发现，与纯TiO2 NW光阳极相比，这种修饰显著提高了光电电化学性能。对于我们最活跃的TiO2@GaOxNy核壳纳米线，GaOxNy厚度为20 nm，在AM 1.5 G照射（100 mW cm - 2）下，光电流密度高达1.10 mA cm - 2（在1.23 V vs. RHE下），比未修饰的TiO2 NWs高14倍。此外，与TiO2匹配的带隙比未修饰的TiO2增强了对可见光的吸收，并且在GaOxNy沉积后容易形成氧空位也为水活化提供了活性位点。对模型体系的密度泛函理论研究证实了高氧原子修饰TiO2的带隙缩小、高还原性和活化水的能力。ALD沉积的高氧原子纳米线（TiO2@GaOxNy）的高效稳定的核壳纳米线系统为制备核壳结构的光电阳极提供了良好的策略，从而提高了光电阳极的光电性能。
As a well-known semiconductor that can catalyse the oxygen evolution reaction, TiO2 has been extensively investigated for its solar photoelectrochemical water properties. Unmodified TiO2 shows some issues, particularly with respect to its photoelectrochemical performance. In this paper, we present a strategy for the controlled deposition of controlled amounts of GaOxNy cocatalysts on TiO2 1D nanowires (TiO2@GaOxNy core–shell) using atomic layer deposition. We show that this modification significantly enhances the photoelectrochemical performance compared to pure TiO2 NW photoanodes. For our most active TiO2@GaOxNy core–shell nanowires with a GaOxNy thickness of 20 nm, a photocurrent density up to 1.10 mA cm−2 (at 1.23 V vs. RHE) under AM 1.5 G irradiation (100 mW cm−2) has been achieved, which is 14 times higher than that of unmodified TiO2 NWs. Furthermore, the band gap matching with TiO2 enhances the absorption of visible light over unmodified TiO2 and the facile oxygen vacancy formation after the deposition of GaOxNy also provides active sites for water activation. Density functional theory studies of model systems of GaOxNy–modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaOxNy core–shell nanowires with ALD deposited GaOxNy demonstrate a good strategy for the fabrication of core–shell structures that enhance the photoelectrochemical performance of readily available photoanodes.