Local Environment of Strontium Cations Activating NaTaO3 Photocatalysts
Local Environment of Strontium Cations Activating NaTaO3 Photocatalysts
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DOI：
10.1021/acscatal.7b03567
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发表时间：
2018-01
期刊：
影响因子：
12.9
通讯作者：
Longjie An;Takuro Sasaki;P. Weidler;C. Wöll;N. Ichikuni;H. Onishi
中科院分区：
文献类型：
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作者：
Longjie An;Takuro Sasaki;P. Weidler;C. Wöll;N. Ichikuni;H. Onishi
钽酸钠，NaTaO 3，是光催化水分解和CO2还原的最佳半导体之一。掺杂金属阳离子对于提高所需反应的量子效率至关重要。然而，与主体金属氧化物的掺杂和通过客体金属阳离子的活化相关的细节并不充分已知。最基本的问题是通过掺杂客体阳离子来提高量子效率，客体阳离子是主体晶格中的杂质。在这项研究中，Sr阳离子，这是典型使用的客体阳离子在NaTaO 3的局部环境，其特征在于扩展的X射线吸收精细结构光谱。结果表明，Sr掺杂的NaTaO 3光催化剂中存在两个Sr-O壳层。具有出乎意料的短Sr-O键长1.96 A的小壳对应于嵌入在TaO 6八面体的角共享网络中的SrO 6八面体。另一个Sr-O键长为2.60 A的壳层对应于SrO_（12）立方八面体，Sr约为0.001。
Sodium tantalate, NaTaO3, is one of the best semiconductors for photocatalytic water splitting and CO2 reduction. Doping with metal cations is crucial for enhancing the quantum efficiency of the desired reactions. Nevertheless, details related to the doping of the host metal oxide and activation by guest metal cations are not sufficiently known. The most fundamental question concerns the increase in the quantum efficiency via doping with guest cations that are impurities in the host lattice. In this study, the local environment of Sr cations, which are the typically used guest cations in NaTaO3, was characterized by extended X-ray absorption fine structure spectroscopy. The results reveal the presence of two Sr–O shells in the Sr-doped NaTaO3 photocatalysts. The small shell with an unexpectedly short Sr–O bond length of 1.96 A corresponds to SrO6 octahedra embedded in the corner-shared network of TaO6 octahedra. The other shell with a Sr–O bond length of 2.60 A corresponds to SrO12 cuboctahedra with Sr ca...