Abstract

Cerium and dysprosium co-doped ZnO nanoparticles were synthesized through a simple co-precipitation approach at low temperature. X-ray diffraction was used for the structure and purity analysis of the samples prepared. A hexagonal wurtzite structure was observed with no secondary peaks. The average particle size was ~35 nm. Morphology was studied using scanning electron microscopy. A change in morphology from elongated nanorods to nanoflowers was observed as the concentration of dopants increased. Photoluminescence spectra confirmed the shift of absorption edge towards the visible region of the solar spectrum. Red shift was confirmed by UV–Vis spectroscopy which also revealed the narrowing of bandgap in co-doped samples. The photocatalytic activity of the nanoparticles was evaluated in photodegradation of rhodamine B (RhB) under UV irradiation. The experiment revealed a total degradation of the organic molecules indicated by the elimination of the dye color. The results showed that ZnO photocatalyst, co-doped with cerium and dysprosium (Zn_0.90Ce_0.05Dy_0.05O), exhibited much improved photocatalytic performance (98% degradation) in comparison to un-doped ZnO. The enhanced photocatalytic performance of co-doped samples could be explained by an increase in the amount of surface oxygen vacancies, improved absorption capacity and delayed recombination of photo generated electrons and holes owing to creation of trap states in the bandgap of ZnO.

中文翻译：

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Ce和Dy共掺杂ZnO纳米颗粒增强的光催化和光致发光性能

摘要

通过简单的共沉淀方法在低温下合成了铈和镝共掺杂的 ZnO 纳米粒子。X射线衍射用于制备样品的结构和纯度分析。观察到六方纤锌矿结构，没有二次峰。平均粒径为~35 nm。使用扫描电子显微镜研究形态学。随着掺杂剂浓度的增加，观察到从细长纳米棒到纳米花的形态变化。光致发光光谱证实了吸收边缘向太阳光谱的可见区域移动。紫外-可见光谱证实了红移，这也揭示了共掺杂样品中带隙的变窄。纳米粒子的光催化活性在紫外线照射下对罗丹明 B (RhB) 的光降解进行了评估。实验表明，染料颜色的消除表明有机分子完全降解。结果表明, ZnO 光催化剂, 共掺杂铈和镝 (Zn_0.90 Ce _0.05 Dy _0.05 O)，与未掺杂的 ZnO 相比，表现出大大改善的光催化性能（98% 降解）。共掺杂样品的光催化性能增强可以通过表面氧空位量的增加、吸收能力的提高以及由于在 ZnO 的带隙中产生陷阱态而延迟光生电子和空穴的复合来解释。