Pure and alkaline earth metal (Ba2+, Ca2+ and Mg2+)-doped tin oxide nanoparticles were synthesized by simple co-precipitation, and their structural, optical, functional, morphological and compositional properties were analyzed in detail using powder X-ray diffraction, UV–visible spectroscopy, photoluminescence spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy and energy-dispersive analysis of X-ray (EDAX). XRD revealed the formation of rutile tetragonal structure, and the crystallite size has decreased from 28 to 24 nm by the addition of alkaline metal dopants. FTIR spectra confirmed the presence of fundamental vibration modes of SnO2. The optical band gap energy was decreased to 3.05, 3.19 and 2.98 eV by introducing Ba2+, Ca2+ and Mg2+ ions, respectively. Photoluminescence spectra showed defect-related emission peaks, and their intensities were found to increase in doped SnO2 samples. EDAX spectra confirmed the presence of Sn, O, Ba, Ca and Mg elements. The photocatalytic activity of pure and alkaline metal-doped SnO2 catalyst has been investigated under visible light irradiation by using methylene blue dye. The results showed that the Mg-doped SnO2 catalyst has a higher photodegradation efficiency (~ 95.7%) compared with other investigated samples.

中文翻译：

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在可见光照射下通过添加碱土金属（Ba2+、Ca2+ 和 Mg2+）改善纳米结构 SnO2 的光催化性能

通过简单的共沉淀法合成了纯碱和碱土金属（Ba2+、Ca2+ 和 Mg2+）掺杂的氧化锡纳米粒子，并使用粉末 X 射线衍射、UV-可见光谱、光致发光光谱、傅里叶变换红外 (FTIR) 光谱、扫描电子显微镜和 X 射线能量色散分析 (EDAX)。XRD显示金红石四方结构的形成，并且通过添加碱金属掺杂剂，微晶尺寸从28nm减小到24nm。FTIR 光谱证实了 SnO2 基本振动模式的存在。通过引入 Ba2+、Ca2+ 和 Mg2+ 离子，光学带隙能量分别降低到 3.05、3.19 和 2.98 eV。光致发光光谱显示出与缺陷相关的发射峰，并且发现它们的强度在掺杂的 SnO2 样品中增加。EDAX 光谱证实了 Sn、O、Ba、Ca 和 Mg 元素的存在。使用亚甲基蓝染料在可见光照射下研究了纯和碱金属掺杂的 SnO2 催化剂的光催化活性。结果表明，与其他研究样品相比，Mg 掺杂的 SnO2 催化剂具有更高的光降解效率（~95.7%）。