Exploiting the Photonic Crystal Properties of TiO2 Nanotube Arrays To Enhance Photocatalytic Hydrogen Production
Exploiting the Photonic Crystal Properties of TiO2 Nanotube Arrays To Enhance Photocatalytic Hydrogen Production
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DOI：
10.1021/acscatal.5b02817
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发表时间：
2016-02-01
期刊：
影响因子：
12.9
通讯作者：
Selli, Elena
中科院分区：
文献类型：
--
作者：
Chiarello, Gian Luca;Zuliani, Alessio;Selli, Elena
在含HF的乙二醇电解质溶液中，采用电化学阳极氧化法在金属钛基体上生长了两个系列的自组装TiO 2纳米管（NT）阵列，并在450 ℃下进行了后煅烧。所获得的薄膜，其特征在于FESEM，XRD，和UV-vis-NIR DRS分析和测试作为光阳极在入射光子电流效率（IPCE）的测量和在两室光电化学电池（PEC）单独的H-2和O-2生产。NT阵列的光催化性能随着阳极化期间施加的电势的增加而显著增加（即，随着NT内径的增加）和光的入射角。IPCE测量显示，这种意外的行为是由于活动阈值的红移，允许收集和转换更大部分的太阳光谱。这一现象归因于光子晶体固有的光子晶体性质引起的光子带隙位置的平行移动，并证明了有序的分级结构在通过限制和操纵光来改善NT阵列的光催化性能方面所发挥的重要作用。
Two series of self-assembled TiO2 nanotube (NT) arrays were grown by electrochemical anodization on a metallic titanium substrate with different anodization times and applied potentials in HF-containing ethylene glycol electrolyte solutions and postcalcined at 450 degrees C. The obtained thin films were characterized by FESEM, XRD, and UV-vis-NIR DRS analyses and tested as photoanodes in incident photon to current efficiency (IPCE) measurements and in a two-compartment photoelectrochemical cell (PEC) for separate H-2 and O-2 production. The photocatalytic performance of the NT arrays significantly increased with an increase in the potential applied during anodization (i.e., with increasing the NT inner diameter) and the incident angle of the light. IPCE measurements revealed that such unexpected behavior is due to a red shift of the activity threshold that allows harvesting and converting a larger portion of the solar spectrum. This phenomenon is ascribed to the parallel shift of the photonic band gap position originated by the intrinsic photonic crystal properties and demonstrates the important role played by ordered hierarchical structures in improving the photocatalytic performance of NT arrays by confining and manipulating light.