In this work, the synthesis of β-AlF_3–x(OH)_x nanoparticles with very high specific surface area (SSA) using a microwave-assisted solvothermal process is reported. The influence of synthesis parameters on the morphology and SSA was investigated, and the nature of the solvent is shown to have the greatest impact. Five samples prepared using different solvent mixtures were deeply characterized by thermogravimetric analysis (TGA), N₂ sorption, powder X-ray diffraction, transmission electron microscopy (TEM), and ¹⁹F and ²⁷Al high-field solid-state NMR. Their SSAs range from 25 to 345 m²·g^–1 with an associated OH content slightly increasing from ≈16% (AlF_2.52(OH)_0.48) to ≈19% (AlF_2.42(OH)_0.58), as estimated by TGA and ²⁷Al high-field solid-state NMR. Compared to previous reference work [Dambournet, D., Chem. Mater. 2008, 204 1459−1469], β-AlF_3–x(OH)_x nanoparticles with SSAs up to 4 times larger were obtained. TEM revealed the formation of hollow nanostructures except when the surface exceeds 300 m²·g^–1, in which case isolated nanoparticles are observed. The sample with the highest SSA also displaying an appealing cumulative pore volume of 0.060 cm³·g^–1, its hydrogen adsorption capability was evaluated to show that β-AlF_3–x(OH)_x nanoparticles have a potential interest for hydrogen storage applications.

中文翻译：

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具有可调比表面积的纳米结构 β-AlF3-x(OH)x 的受控形态合成

在这项工作中，报道了使用微波辅助溶剂热法合成具有非常高比表面积 (SSA)的 β-AlF _{3- x} (OH) _x纳米颗粒。研究了合成参数对形态和 SSA 的影响，结果表明溶剂的性质影响最大。通过热重分析 (TGA)、N ₂吸附、粉末 X 射线衍射、透射电子显微镜 (TEM) 以及¹⁹ F 和²⁷ Al 高场固态核磁共振对使用不同溶剂混合物制备的五个样品进行了深入表征。它们的 SSA 范围从 25 到 345 m ² ·g ^–1根据 TGA 和²⁷ Al 高场固态 NMR估计，相关的 OH 含量从 ≈16% (AlF _2.52 (OH) _0.48 ) 到 ≈19% (AlF _2.42 (OH) _0.58 ) 。与之前的参考工作相比 [丹伯内，D.，化学。母校。 2008 , 20 4 1459-1469]，获得了 β-AlF _{3- x} (OH) _x纳米粒子，其 SSA 最大可达 4 倍。TEM 揭示了空心纳米结构的形成，除非当表面超过 300 m ² ·g ^{–1 时}，在这种情况下观察到孤立的纳米粒子。具有最高 SSA 的样品也显示出吸引人的 0.060 cm ³ ·g ^–1累积孔体积，评估其氢吸附能力以表明 β-AlF _{3- x} (OH) _x纳米颗粒具有储氢应用的潜在兴趣.