This contribution reports on the optical properties of biosynthesised ${\rm{Eu}_2}{{\rm{O}}_3}$ nanoparticles bioengineered for the first time by a green and cost effective method using aqueous fruit extracts of Hyphaene thebaica as an effective chelating and capping agent. The morphological, structural, and optical properties of the samples annealed at 500°C were confirmed by using a high-resolution transmission electron microscope (HR-TEM), x-ray diffraction analysis (XRD), UV–Vis spectrocopy, and photoluminescence spectrometer. The XRD results confirmed the characteristic body-centered cubic (bcc) structure of ${\rm{Eu}_2}{{\rm{O}}_3}$ nanoparticles with an average size of 20 nm. HR-TEM revealed square type morphology with an average size of ${\sim}{{6}}\;{\rm{nm}}$. Electron dispersion energy dispersive x-ray spectroscopy spectrum confirmed the elemental single phase nature of pure ${\rm{Eu}_2}{{\rm{O}}_3}$. Furthuremore, the Fourier transformed infrared spectroscopy revealed the intrinsic characteristic peaks of ${\rm{Eu}} {-} {\rm{O}}$ bond stretching vibrations. UV–Vis reflectance proved that ${\rm{Eu}_2}{{\rm{O}}_3}$ absorbs in a wide range of the solar spectrum from the VUV–UV region with a bandgap of 5.1 eV. The luminescence properties of such cubic structures were characterized by an intense red emission centered at 614 nm. It was observed that the biosynthesized ${\rm{Eu}_2}{{\rm{O}}_3}$ nanoparticles exhibit an efficient red-luminescence and hence a potential material as red phosphor.

中文翻译：

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用于红色发光应用的生物合成纳米级 Eu2O3 的光学特性

该贡献报告了生物合成的${\rm{Eu}_2}{{\rm{O}}_3}$纳米粒子的光学特性，该纳米粒子首次通过绿色和具有成本效益的方法使用Hyphaene thebaica 的含水水果提取物作为生物工程一种有效的螯合剂和封端剂。通过使用高分辨率透射电子显微镜 (HR-TEM)、X 射线衍射分析 (XRD)、紫外-可见光谱和光致发光光谱仪确认了在 500°C 下退火的样品的形态、结构和光学特性. XRD 结果证实了${\rm{Eu}_2}{{\rm{O}}_3}$纳米颗粒的特征体心立方 (bcc) 结构，平均尺寸为 20 nm。HR-TEM 显示方形形态，平均尺寸为${\sim}{{6}}\;{\rm{nm}}$ . 电子色散能量色散 X 射线光谱证实了纯${\rm{Eu}_2}{{\rm{O}}_3}$的元素单相性质。此外，傅里叶变换红外光谱揭示了${\rm{Eu}} {-} {\rm{O}}$键伸缩振动的固有特征峰。UV-Vis 反射证明${\rm{Eu}_2}{{\rm{O}}_3}$在 VUV-UV 区域的宽范围太阳光谱中吸收，带隙为 5.1 eV。这种立方结构的发光特性的特征在于以 614 nm 为中心的强烈红色发射。观察到生物合成的${\rm{Eu}_2}{{\rm{O}}_3}$ 纳米粒子表现出有效的红光发光，因此是一种潜在的材料作为红色磷光体。