一步法水热合成TiO_2纳米线及其光催化性能

One-step Hydrothermal Synthesis of TiO_2 Nanowires and Their Photocatalytic Activities

以钛酸丁酯和异丙醇为原料,采用一步法在NaOH溶液中水解后直接进行水热反应,经焙烧处理,得到TiO2纳米线.采用扫描电子显微镜(SEM)、X射线衍射(XRD)和能谱分析(EDX)对产物进行了形貌、结构及成分的表征.考察了不同水热温度、碱液浓度、水热反应时间及焙烧温度等因素对产物的影响.结果表明,获得较好形貌TiO2纳米线的最佳水热温度、碱液浓度和水热反应时间分别是180℃,10 mol/L和24 h.所得TiO2纳米线焙烧至950℃时仍为锐钛矿相,说明本文制备方法迟滞了TiO2纳米线由锐钛矿相向金红石相的转变.以甲基橙为目标降解物,采用紫外-可见分光光度计研究了未掺杂和铕掺杂TiO2纳米线(Eu-TiO2)的光催化性能.结果显示,最佳掺铕量(摩尔分数)为1.6%.在300 W紫外灯照射60 min时,此掺铕量的TiO2纳米线对甲基橙溶液的降解率是未掺杂样品的1.5倍.

Titanium dioxide（TiO： ） nanowires were synthesized by one-step hydrothermal method using tetrabutyl titanate, isopropanol and sodium hydroxide as starting materials. The synthesized TiO2 nanowires were characterized by scanning electron microscopy（SEM）, X-ray diffraction （XRD） and energy dispersive X-ray spectrometry （EDX）. The effects of reaction temperature, concentration of sodium hydroxide and reaction time on the formation of the nanowires were investigated. It is found that the optimum reaction temperature, concentration of sodium hydroxide and reaction time for the formation of high quality TiO2 nanowires are 180 ℃, 10 mol/L and 24 h, respectively. The nanowires were still anatase phase even if the calcination temperature increased to 950 ℃ , indicating that the phase transition of TiO2 from anatase to rutile was delayed. In addition, the photocatalytic activities of pure TiO2 nanowires and TiO2 nanowires doped with Eu were studied under the irradiation of 300 W UV-lamp for 60 min, using methyl orange solution as the target degradation material. The results indicate that the degradation ratio of Eu-doped TiO2 nanowires is 1.5 times that of pure TiO2 nanowires, and the optimum doping amount of Eu is 1.6%.