Three-dimensional Gd-doped TiO2 fibrous photoelectrodes for efficient visible light-driven photocatalytic performance
Three-dimensional Gd-doped TiO2 fibrous photoelectrodes for efficient visible light-driven photocatalytic performance
复制标题
DOI：
10.1039/c3ra46851h
复制
发表时间：
2014-01-01
期刊：
影响因子：
3.9
通讯作者：
Paik, Ungyu
中科院分区：
文献类型：
--
作者：
Choi, Junghyun;Sudhagar, P.;Paik, Ungyu
为了阐明电极几何形状对TiO 2光催化性能的影响，本文报道了使用简单的静电纺丝技术合成三维原位Gd掺杂TiO 2纳米纤维（TiO 2-NFs）。与TiO 2纳米粒子（TiO 2-NPs）（k = 0.006 m（-1））电极相比，初纺态TiO 2-NFs具有更高的光催化活性（k = 0.013 m（-1）），这可能归因于一维纳米纤维中的快速电子传输。此外，Gd掺杂的TiO 2-NFs显示出近五倍的PC降解速率的增强，由于协同更高的电子传输和生产的HO中心点，由于形态和掺杂的影响，分别。与此形成鲜明对比的是，Gd掺杂由于晶界增加而对TiO 2-NPs的PC活性没有影响，这表明电极结构的重要作用。采用密度泛函理论（DFT）研究了Gd掺杂纯TiO 2的机理。利用紫外光电子能谱（UPS）和Mott-Schottky分析，详细讨论了Gd掺杂和电极结构对TiO 2中电荷复合和平带电位变化的影响，并讨论了这些发现对设计掺杂3D纤维光电极的意义。
To elucidate the influence of electrode geometry on the photocatalytic performance of TiO2, herein, we report the synthesis of three-dimensional in situ Gd-doped TiO2 nanofibers (TiO2-NFs) using a simple electrospinning technique. The as-spun pristine TiO2-NFs show a higher photocatalytic (PC) activity (k = 0.013 m(-1)) than the TiO2 nanoparticles (TiO2-NPs) (k = 0.006 m(-1)) electrode, which could be attributed to the fast electron transport in the 1D NFs. In addition, Gd-doped TiO2-NFs show nearly five-fold enhancement in the PC degradation rate due to synergistically higher electron transport and production of HO center dot due to the effects of morphology and doping, respectively. In striking contrast, Gd-doping has no influence on the PC activity of TiO2-NPs due to increased grain boundaries, signifying the vital role of the electrode architecture. The mechanism of Gd doping in pure anatase TiO2 is investigated using density functional theory (DFT) calculations. The influence of Gd-doping and the electrode architecture on the charge recombination and flat-band potential variation in TiO2 are discussed elaborately using ultraviolet photoelectron spectroscopy (UPS) and Mott-Schottky analysis, and the implications of these findings for designing doped 3D fibrous photoelectrodes are discussed.