核壳结构Ta₂O₅@Ta₃N₅纳米花控制合成工艺研究
Controllable Synthesis of Core-Shell Structure Ta₂O₅@Ta₃N₅ Nanoflowers

以TaCl₅为钽源，采用水热–高温氮化法合成核壳结构Ta₂O₅@Ta₃N₅纳米花。首先，利用场发射扫描电子显微镜(SEM)测试评价样品形貌，研究溶剂种类、异丙醇用量、盐酸用量、水热时间等条件因素对样品形貌调控规律；异丙醇溶剂有利于促进棒状结构生成，当异丙醇用量为14 mL，浓盐酸用量为400 μL，经160℃水热4 h制得Ta₂O₅纳米花，组成纳米花的棒状结构直径约50 nm，长约200 nm。再利用高温氮化技术，在50 mL？min？1 NH3气流下，经850℃氮化3 h，Ta₂O₅纳米花经拓扑转换制得核壳结构Ta₂O₅@Ta₃N₅纳米花。XRD分析证实样品具有Ta₂O₅和Ta₃N₅双相结构，晶化度较高；HRTEM分析表明样品形成Ta₂O₅/Ta₃N₅；BET比表面积为21.9 m²？g^？1。本文为进一步开展Ta₂O₅@Ta₃N₅基纳米材料的制备及应用性能研究奠定实验技术基础。
Ta2O5@Ta3N5 nanoflowers were synthesized by a combination of hydrothermal and high-tempe- rature nitridation method, using TaCl₅ as the tantalum source. Based on the morphology evaluated by field emission scanning electron micros-copy (SEM), the preparation process of Ta₂O₅ nanoflowers was optimized by regulating process conditions including solvent type, amount of isopropanol, amount of hydrochloric acid, and hydrother-mal time. Isopropanol solvent is beneficial to promote the formation of rod-like structure. When the amount of isopropanol is 14 mL and the amount of concentrated hydrochloric acid is 400 μL, Ta₂O₅ nanoflowers are prepared by hydrothermal treatment at 160？C for 4 h. The rod-like structure of nanoflowers is about 50 nm in diameter and about 200 nm in length. Then, Ta₂O₅@Ta₃N₅ nanoflowers were prepared by topological transformation of Ta₂O₅ nanoflowers, using high-temperature nitriding technology, under 50 mL？min^？1 NH₃ gas flow, after nitriding at 850？C for 3 h. XRD analysis confirmed that the sample possessed both Ta₂O₅ and Ta₃N₅ phases with a high crystallization de-gree. HRTEM analysis indicated that the sample exhibited core-shell structure Ta₂O₅@Ta₃N₅. Its BET specific area was 21.9 m²？g^？1. This work lays an experimental technical foundation for further research on preparation and application