Comparison of two- and three-layer restacked Dion-Jacobson phase niobate nanosheets as catalysts for photochemical hydrogen evolution
Comparison of two- and three-layer restacked Dion-Jacobson phase niobate nanosheets as catalysts for photochemical hydrogen evolution
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DOI：
10.1039/b903692j
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发表时间：
2009-01-01
影响因子：
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通讯作者：
Mallouk, Thomas E.
中科院分区：
文献类型：
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作者：
Maeda, Kazuhiko;Mallouk, Thomas E.
通过用四（正丁基）氢氧化铵剥离相应的Dion-Jacobson型层状钙钛矿（HCa 2Nb 3 O 10、HSr 2Nb 3 O 10和HLaNb 2 O 7）并随后用盐酸处理来制备重新堆叠的层状钙钛矿纳米片。通过X射线衍射、扫描电子显微镜、拉曼光谱和漫反射光谱对纳米片进行了表征。通过铂纳米颗粒作为附加催化剂的改性，这些纳米片材料被测试为在紫外线照射（λ> 300 nm）下从含有2-丙醇作为电子供体的水中析氢的光催化剂。三层纳米片（HSr 2Nb 3 O 10）的活性比具有双钙钛矿层的HLaNb 2 O 7纳米片高一个数量级，尽管它们的物理化学相似。物理化学分析表明，在三层钙钛矿纳米片中，光催化活性受到几个因素的影响，包括导带电位和带隙能量（可用光子的数量），这是由NbO 6八面体组成的钙钛矿块的畸变引起的。
Restacked niobate nanosheets were prepared by exfoliation of the corresponding Dion-Jacobson type layered perovskites (HCa2Nb3O10, HSr2Nb3O10 and HLaNb2O7) with tetra(n-butyl)ammonium hydroxide and subsequent treatment with hydrochloric acid. The nanosheets were characterized by means of X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and diffuse reflectance spectroscopy. With modification by platinum nanoparticles as additional catalysts, these nanosheet materials were tested as photocatalysts for hydrogen evolution from water containing 2-propanol as an electron donor under ultraviolet irradiation (lambda > 300 nm). The activity of a triple-layered nanosheet (HSr2Nb3O10) was an order of magnitude higher than that of the HLaNb2O7 nanosheet with double perovskite layers, despite their physicochemical similarity. Physicochemical analyses suggested that in triple-layered perovskite nanosheets, photocatalytic activity is influenced by several factors including the conduction band potential and the band-gap energy (the number of available photons), which are derived from the distortion of perovskite blocks consisting of NbO6 octahedra.