Synthesis of ordered mesoporous uranium dioxide by a nanocasting route
Synthesis of ordered mesoporous uranium dioxide by a nanocasting route
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DOI：
10.1515/ract-2015-2563
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发表时间：
2016
影响因子：
1.8
通讯作者：
Ran Zhao;Lin Wang;Z. Chai;W. Shi
中科院分区：
文献类型：
--
作者：
Ran Zhao;Lin Wang;Z. Chai;W. Shi
摘要以六水合硝酸铀酰为金属前驱体，以不同的有序介孔氧化硅（KIT-6和SBA-15）为模板，采用纳米浇铸法，首次合成了具有三维结构（UO 2-KIT-6）和纳米线束（UO 2-SBA-15）的有序介孔UO 2。将硝酸铀酰浸渍到二氧化硅模板的中孔中，并在第一步后转化为U3 O 8。在700°C、5%H2/Ar气氛下，用SiO2复合材料还原介孔U3 O 8，然后进行模板去除，合成了有序的UO 2介孔结构。所制备的UO 2-KIT-6具有几毫米的颗粒尺寸，并且由未偶联的亚骨架介观结构和结晶壁构成，而UO 2-SBA-15具有绳状形貌，并且由纳米线阵列组成。有序UO 2介观结构的表面积和孔体积对于UO 2-KIT-6分别为47.2 m2 g−1和0.23 cm 3 g−1，对于UO 2-SBA-15分别为54.4 m2 g−1和0.28 cm 3 g−1。
Abstract Ordered mesoporous UO2 with 3-D structure (for UO2-KIT-6) and nanowire bundles (for UO2-SBA-15) was synthesized for the first time by a nanocasting route using different ordered mesoporous silica (KIT-6 and SBA-15, respectively) as templates and uranyl nitrate hexahydrate as the metal precursor. The uranyl nitrate was impregnated into the mesopore of the silica template and was converted to U3O8 after the first step. The synthesis of ordered UO2 mesostructure was achieved by reducing the mesoporous U3O8 with silica composites under 5% H2/Ar atmosphere at 700°C, followed by a template removal process. The as-prepared UO2-KIT-6 had a particle size of several millimeters, and was constructed with uncoupled subframework mesostructure and crystalline walls, while UO2-SBA-15 possessed a rope-like morphology and consisted of nanowire arrays. The surface area and pore volume of ordered UO2 mesostructure are 47.2 m2 g−1 and 0.23 cm3 g−1 for the UO2-KIT-6, and 54.4 m2 g−1 and 0.28 cm3 g−1 for the UO2-SBA-15, respectively.