Oxygen vacancy induces self-doping effect and metalloid LSPR in non-stoichiometric tungsten suboxide synergistically contributing to the enhanced photoelectrocatalytic performance of WO3-x/TiO2-x heterojunction
Oxygen vacancy induces self-doping effect and metalloid LSPR in non-stoichiometric tungsten suboxide synergistically contributing to the enhanced photoelectrocatalytic performance of WO3-x/TiO2-x heterojunction
复制标题
氧空位在非化学计量低氧化钨中诱导自掺杂效应和类金属局域表面等离子体共振协同增强WO3-x/TiO2-x异质结的光电催化性能
DOI：
10.1039/c8cp02044b
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发表时间：
2018-07-07
影响因子：
3.3
通讯作者：
Cao, Wenwu
中科院分区：
文献类型：
--
作者：
Huang, Weicheng;Wang, Jinxin;Cao, Wenwu
设计了一种WO 3-x/TiO 2-x纳米管阵列（NTA）异质结光阳极，通过建立非化学计量比低氧化钨的空位诱导自掺杂效应和局域表面等离子体共振（LSPR）效应的协同效应来提高光电催化（PEC）性能。通过阳极氧化形成TiO 2纳米管阵列，磁控溅射存款类金属WO 3-x，后氢还原在TiO 2-x中形成氧空位并晶化，制备了WO 3-x/TiO 2-xNTA异质结光阳极。由于这种协同效应，WO 3-x/TiO 2-x比WO 3-x/TiO 2、WO 3/TiO 2和TiO 2显示出更高的光捕获能力、更强的光电流响应和由此产生的更好的光电催化性能，证实了氧空位在改善PEC性能中的重要性。采用密度泛函理论计算了样品的电子结构特征，揭示了氧空位对光学性质的影响。研究表明，WO 3-x/TiO 2-xNTA的载流子浓度调谐机制和电荷转移模型与自掺杂和类金属LSPR效应的协同作用有关。
A WO3-x/TiO2-x nanotube array (NTA) heterojunction photoanode was strategically designed to improve photoelectrocatalytic (PEC) performance by establishing a synergistic vacancy-induced self-doping effect and localized surface plasmon resonance (LSPR) effect of metalloid non-stoichiometric tungsten suboxide. The WO3-x/TiO2-x NTA heterojunction photoanode was synthesized through a successive process of anodic oxidation to form TiO2 nanotube arrays, magnetron sputtering to deposit metalloid WO3-x, and post-hydrogen reduction to engender oxygen vacancy in TiO2-x as well as crystallization. On the merits of such a synergistic effect, WO3-x/TiO2-x shows higher light-harvesting ability, stronger photocurrent response, and resultant improved photoelectrocatalytic performance than the contrast of WO3-x/TiO2, WO3/TiO2 and TiO2, confirming the importance of oxygen vacancies in improving PEC performance. Theoretical calculation based on density functional theory was applied to investigate the electronic structural features of samples and reveal how the oxygen vacancy determines the optical property. The carrier density tuning mechanism and charge transfer model were considered to be associated with the synergistic effect of self-doping and metalloid LSPR effect in the WO3-x/TiO2-x NTA.