【摘要】 目的通过水热拓扑合成制备具有光催化活性并暴露特定晶面的Nb₂O₅纳米带。方法以Nb₂O₅和KCl为原料制备的一维KNb₃O₈带状粒子为前驱体,经过酸交换、水热拓扑结构转型得到暴露特定结晶面的单斜相五氧化二铌（M-Nb₂O₅）。用XRD, FE-SEM, TEM, SAED和EDX等分析手段对合成产物的结构、形貌以及化学组成进行表征。结果制备出与前躯体KNb₃O₈粒子形貌相同且主要暴露面为（001）面的单斜相Nb₂O₅带状晶体,其长度为2～8μm,宽度约为500 nm,厚度为50～70 nm。通过模拟阳光下分解水评估了单斜相Nb₂O₅纳米带作为光催化剂的光电化学性能,结果显示其产生的光电流密度及产氢量分别为30.9μA·cm^-2和461μmol·h^-1·g^-1,是对照样品正交相Nb₂O₅粒子的3倍。说明单斜相Nb₂O₅纳米带具有良好的光电化学活性和较高的光电转换效率。结论单斜相Nb₂O₅纳米带晶在光催化剂和光伏纳米器件中具有潜在的应用价值。更多还原

【Abstract】 Purposes—To prepare Nb₂O₅ nanobelts with photocatalytic activity and exposed specific crystal facets by hydrothermal topological synthesis. Methods—With one-dimensional KNb₃O₈ banded particles, which is prepared from Nb₂O₅ and KCl, as the precursor, the monoclinic phase niobium pentoxide（M-Nb₂O₅） exposed specific crystal facets is obtained after acid exchange and hydrothermal topological structure transformation. Then the structure, morphology and chemical composition of the synthesized products were characterized with XRD, FE-SEM, TEM, SAED and EDX. Result—The monoclinic Nb₂O₅ banded crystals exposed mainly the（001） facet were prepared with the same morphology as the precursor KNb₃O₈. Their length is 2～8 μm, width is about 500 nm, and thickness is 50～70 nm. The visible photo-electrochemical performance of the M-Nb₂O₅ nanobelts as photocatalyst was evaluated by splitting water under simulated sunlight. The results showed that the photocurrent density and the amount of evolved H₂ were 30.9 μA·cm^-2 and 461 μmol·h^-1·g^-1, respectively, which is 3 times of the orthorhombic Nb₂O₅ particles of the control group. It indicates that the monoclinic Nb₂O₅ nanobelts have excellent photo-electrochemical activity and high photoelectric conversion efficiency. Conclusion—The monoclinic Nb₂O₅ nanobelt crystals have potential application value in photocatalysts and photovoltaic nanodevices.更多还原