Simple liquid-phase approaches for the synthesis of nanomaterials are attractive because their low costs, reduced nanoparticle aggregation, and compatibility with subsequent liquid processes widen the application scope of the resulting materials. This would be particularly interesting for β-Ga₂O₃ nanoparticles, which often suffer from aggregation issues during their synthesis processes. In this paper, we report a one-step synthesis of β-Ga₂O₃ nanoparticles in supercritical isopropanol. By simply heating Ga(NO₃)₃ in isopropanol at 400 °C for 24 hours, β-Ga₂O₃ nanoparticles with a size of ∼100 nm are obtained without requiring additional calcination in air. A structural characterization comprising X-ray diffraction, scanning electron microscopy, selected-area electron diffraction with transmission electron microscopy, and X-ray absorption fine structure measurements suggest that the synthesis process involves an initial conversion of Ga(NO₃)₃ to Ga(Oi-Pr)₃ or a related species at 80 °C, which then transforms into γ-Ga₂O₃ nanoparticles upon increasing the temperature, to eventually produce β-Ga₂O₃ nanoparticles most likely via a dissolution and recrystallization process.

中文翻译：

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结晶良好的β-Ga2O3纳米颗粒在异丙醇中的一步溶剂热合成及生长机理

用于合成纳米材料的简单液相方法很有吸引力，因为它们的成本低、纳米颗粒聚集减少以及与后续液体工艺的兼容性拓宽了所得材料的应用范围。这对于 β-Ga ₂ O ₃纳米颗粒特别有趣，因为它们在合成过程中经常遇到聚集问题。在本文中，我们报告了一种在超临界异丙醇中一步合成 β-Ga ₂ O ₃纳米颗粒的方法。通过简单地将 Ga(NO ₃ ) ₃在异丙醇中在 400 °C 下加热24 小时，β-Ga ₂ O ₃无需在空气中进行额外的煅烧，即可获得尺寸约为 100 nm 的纳米颗粒。包括 X 射线衍射、扫描电子显微镜、选择区域电子衍射和透射电子显微镜以及 X 射线吸收精细结构测量的结构表征表明合成过程涉及 Ga(NO ₃ ) ₃到 Ga( Oi-Pr) ₃或相关物质在 80 °C 下，然后在升高温度时转化为 γ-Ga ₂ O ₃纳米颗粒，最终最有可能通过溶解和重结晶过程产生 β-Ga ₂ O ₃纳米颗粒。