| 通过相变制备多孔Nb2O5 |
| Formation of Porous Niobium Pentoxide via Phase Transformation |
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| 摘要: 以铌金属为“牺牲”阳极，在无隔膜电解槽中，采用电化学一步法制备了Nb2O5粉体的前驱体铌醇盐，铌醇盐直接水解得胶状沉淀，烘干后的胶状产物在不同热处理条件下产生的相变形成了多孔Nb2O5粉体。采用IR、TG-DSC、XRD、SEM分别对烘干后胶状产物及多孔Nb2O5进行表征。结果表明：无定型的Nb2O5在873 K煅烧后形成2 μm的球形二次颗粒，同时转变为正交晶型，而在1 173 K热处理后转变为单斜Nb2O5的同时，相变伴随Nb2O5球形颗粒向棒状结构的形貌变化，在颗粒颈部连接作用下，最终形成了多孔Nb2O5，孔径为250 nm左右。 |
| 关键词: 铌醇盐 相变 五氧化二铌 多孔结构 |
| 基金项目: |
| Abstract: Niobium(Ⅴ) alkoxides were directly prepared in a undivided electrolytic cell by using niobium metal as sacrificing anode , then niobium(Ⅴ) alkoxides were directly hydrolyzed to gel-like deposits. The phase transformation of the gel-like product by heat treatments resulted in the formation of porous niobium pentoxide. IR, TG-DSC, XRD and SEM were used to characterize the structure of porous Nb2O5 and the gel-like products. Studies show that amorphous Nb2O5 secondary particles change into orthorhombic phase and form 2 μm spherical particles after calcination at 873 K. While monoclinic Nb2O5 is obtained after calcination at 1 173 K, the porous Nb2O5 with pore size of about 250 nm is finally formed following the phase transformation of spherical Nb2O5 particles into rod like particles. |
| Keywords: Niobium(Ⅴ) alkoxides phase transformation niobium pentoxide, porous structure |
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| 摘要点击次数: 1268 |
| 全文下载次数: 1997 |
| 尚鸿艳,梅 华,周幸福,范益群.通过相变制备多孔Nb2O5[J].无机化学学报,2008,24(11):1812-1815. |
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