Herein, the TiO₂–SnO₂ core–shell structures with the core‐to‐shell molar ratios of 5:0.5, 5:0.67, and 5:1 are synthesized by the sol–gel route, and then the structural and optical properties of the synthesized samples are investigated. In order to characterize the samples, the XRD, Raman, FESEM, and TEM techniques are used for their structural verification, while the UV–visible and photoluminescence spectra are used for their optical characterization. The XRD results obtained showed that the annealed TiO₂ sample has an anatase tetragonal structure and that the core–shell samples contain the diffraction peaks of both the core TiO₂ and the shell SnO₂. The XRD results obtained are supported by Raman spectroscopy. The TEM images obtained show evidence of the formation of the composite (core–shell) nanostructure in the samples. The optical investigation shows that the band gaps of the core–shell samples are indirect, like the TiO₂ core itself, and increase with an increase in the core‐to‐shell molar ratio. These results also show that the synthesized core–shell samples are suitable candidates for use in optoelectronic devices.

中文翻译：

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溶胶-凝胶法合成TiO2-SnO2核-壳结构和光学性质的研究

在这里，通过溶胶-凝胶法合成了核壳比为5：0.5、5 ：0.67和5：1的TiO ₂ -SnO ₂核壳结构，然后给出了结构和光学性质对合成样品的一部分进行了研究。为了表征样品，使用XRD，拉曼，FESEM和TEM技术进行结构验证，同时使用UV-可见光谱和光致发光光谱进行光学表征。XRD结果表明，退火后的TiO ₂样品具有锐钛矿四方结构，核-壳样品同时包含核TiO ₂和壳SnO ₂的衍射峰。。拉曼光谱法支持获得的XRD结果。获得的TEM图像显示了样品中复合（核-壳）纳米结构形成的证据。光学研究表明，核壳样品的带隙是间接的，就像TiO ₂核本身一样，并且随着核壳摩尔比的增加而增加。这些结果还表明，合成的核-壳样品适合用于光电器件。