Photoluminescence and Photocatalysis Properties of Dual-Functional Eu3+-Doped Anatase Nanocrystals

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• 作者：Meiqi Chang ; Yanhua Song ; Ye Sheng ; Jie Chen ; Hongxia Guan ; Zhan Shi ; Xiuqing Zhou ; Keyan Zheng ; Haifeng Zou
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：February 2, 2017
• 年：2017
• 卷：121
• 期：4
• 页码：2369-2379
• 全文大小：863K
• ISSN：1932-7455

文摘

Red-color-emitting TiO₂:Eu³⁺ nanophosphors have been synthesized through the hydrothermal process. Samples with different morphologies have been obtained by changing pH values of solution. The structural and luminescence properties of samples were investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis spectra, and photoluminescence (PL) spectra. Most importantly, surface photovoltage spectra were used to discuss the charge transfer process and further explained the luminescence phenomenon of different morphologies for the first time. The critical transfer distance for the Eu³⁺ ions in TiO₂ matrix was calculated, and we could conclude that the concentration quenching process was attributed to the multipole–multipole interaction. The relative intensity ratios of ⁵D₀–⁷F₂ transition to ⁵D₀–⁷F₁ transition of TiO₂:x%Eu³⁺ (x = 2, 4, 6, 8, 10, 12) have been calculated to understand the lattice symmetry and coordination environment of Eu³⁺ ions. The spectral characteristics and site symmetry have been discussed through the Judd–Ofelt parameters. Moreover, the investigation of photocatalytic ability of TiO₂:x%Eu³⁺ showed that the photodegradation efficiencies decrease with an increase in the amount of Eu³⁺ for the degradation of methyl orange under white light irradiation, and the photodegradation efficiency of TiO₂:2%Eu³⁺ was 99% after 25 min, which is much more higher than that for TiO₂:12%Eu³⁺ (25%).