形貌可控氧化铌纳米棒阵列薄膜的合成研究

摘要

Morphology-controlled niobium oxide nanorods array were successfully prepared in a mixed NH4F and H2O2 solution by using niobium powder as the starting materials via hydrothermal method. The morphology and composition of niobium oxide film were characterized by X-ray diffraction patteras(XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), respectively. The reaction time and hydrothermal temperature and concentration of NH4F, which affect the final composition and morphology of niobium oxide films, were also investigated in details. The results show that niobium oxide crystal have a strong anisotropy growth in the presence of NH4F and H2O2, which guides the oriented growth of hexagonal nanorods array on the niobium powder surface. The concentration of NH4F play great roles in the formation of the final products, the morphological of niobium oxide film is transformed from polyhedron granule to circular nanorods array and aggregated nanoparticles with the increase of NH4F concentration. Niobium oxide nanorods arrays can be obtained at Nb substrate after hy-thermal reaction at 150℃ for 10h with adding 0.5g NH4F. A formation mechanism is also proposed.%以铌金属为原料,在NH4F和H2O2的体系中,通过水热方法制备形貌可控的氧化铌纳米棒阵列薄膜.采用XRD、SEM、TEM等对不同工艺条件下获得的产物微观形貌和组成进行了表征,考察了水热时间、水热温度和NH4F浓度对最终产物及形貌的影响.研究表明:氧化铌在NH4F和H2O2共存下表现出各向异性生长特性.NH4F用量对最终产物及形貌起重要作用,随着NH4F浓度的增加,Nb2O5薄膜形貌由多面体状颗粒,向近圆形纳米棒阵列和无规则的纳米颗粒团聚体演变.当NH4F的浓度为0.5g,水热反应温度为150℃反应10h,氧化铌在铌金属表面定向生长为六边形的纳米棒阵列.本文还提出了氧化铌纳米棒阵列薄膜的形成机理.