表面活性剂对BiFeO_3单晶纳米线形貌和光学性能的影响

Effect of surfactant on the morphology and optical performance of BiFeO_3 single crystal nanowires

为了探究表面活性剂对BiFeO_3单晶纳米线形貌及性能的影响,采用沉淀法制备前驱体,并辅以表面活性剂采用水热法制备BiFeO_3纳米线,利用X线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和UV3600分光光度计对不同量和种类的表面活性剂以及不同水热反应时间下所得BiFeO_3纳米线的微观形貌、结构和性能进行测试分析.实验结果表明:适当的表面活性剂浓度以及恰当的水热温度和时间有利于BiFeO_3纳米线的形成,140℃的水热温度、48 h的反应时间以及0.0605g的十六烷基三甲基溴化铵(C_(16)H_(33)(CH_3)_3NBr,CTAB)反应所得BiFeO_3纳米线的表面形貌最好;TEM和选区域电子衍射(SAED)结果表明制备所得样品为单晶,且具有高度结晶性,XRD结果表明所得BiFeO_3纳米线为纯相;所得BiFeO_3纳米线在可见光范围均有较好的吸收,且带隙为1.8 e V.此外,通过对比实验数据可知BiFeO_3纳米线的形成机制与晶体成核和晶体生长间的竞争作用以及晶体选择性吸附生长有关.

To explore the effect of surfactant on the morphology and properties of BiFeO3 single crystal nanowires, BiFeO3nanowires were prepared by hydrothermal method with various amount of surfactant. The microstructure and optical propertiesof BiFeO3 nanowires were analyzed by X-ray diffractometer （ XRD）, Scanning electron microscopy （ SEM）, Transmissionelectron microscopy （ TEM） and UV3600 spectrophotometer. The experiment results show that the suitable surfactant con-centration, appropriate hydrothermal temperature and time can dramatically influence the formation of BiFeO3 nanowires.The surface topography of BiFeO3 nanowires is best when reaction temperature is 140 , reaction time is 48 h and the ad-dition of CTAB （ C16H33 （ CH3 ）3NBr）is 0.060 5 g. Transmission electron microscope（ TEM）and selective area electron diffraction（ SAED） indicates that the sample is single crystal, and it has a high degree of crystallinity. XRD results show that theBiFeO3 nanowires have the pure phase. The BiFeO3 nanowires has a better absorption in the spectrum of visible light, and itsband gap is 1.8 eV. In addition, a growth mechanism of BiFeO3 nanowire is related to the competition between crystal nucleationand crystal growth and selective adsorption growth of the crystal by contrasting experimental data.