One-step hydrothermal fabrication and photocatalytic activity of surface-fluorinated TiO2 hollow microspheres and tabular anatase single micro-crystals with high-energy facets
One-step hydrothermal fabrication and photocatalytic activity of surface-fluorinated TiO2 hollow microspheres and tabular anatase single micro-crystals with high-energy facets
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DOI：
10.1039/b914385h
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发表时间：
2010-02
期刊：
影响因子：
3.1
通讯作者：
Jiaguo Yu;Quanjun Xiang;J. Ran;S. Mann
中科院分区：
文献类型：
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作者：
Jiaguo Yu;Quanjun Xiang;J. Ran;S. Mann
以氟化氢铵(NH4HF2)为形貌控制剂，采用一步水热法制备了表面氟化的二氧化钛中空微球和具有高能(001)晶面的板状锐钛矿型单晶。用扫描电子显微镜、透射电子显微镜、X射线衍射仪、X射线光电子能谱和氮气吸附-脱附等温线对样品进行了表征。以对苯二甲酸为探针分子，用光致发光(PL)技术检测了二氧化钛表面·OH自由基的产生。通过对罗丹明B(RhB)水溶液的常温光催化脱色，评价了所制备的样品的光催化活性。结果表明，通过改变NH4HF2的浓度可以很容易地控制样品的颗粒形貌、平均微晶尺寸、比表面积、孔结构和光催化活性。随着NH4HF2浓度的增加，平均微晶尺寸和平均孔径增大，比表面积、孔体积和孔隙率逐渐减小。当氟钛摩尔比(Rf)保持在0~1的范围内时，制得的样品的光催化活性超过了Degussa P25(P25)。
Surface-fluorinated TiO2 hollow microspheres and tabular-shaped anatase single micro-crystals with highly energetic (001) facets exposed were prepared by a one-step hydrothermal strategy using ammonium bifluoride (NH4HF2) as a morphology controlling agent. The prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and N2 adsorption–desorption isotherms. Production of ˙OH radicals on the TiO2 surface was detected by a photoluminescence (PL) technique using terephthalic acid as a probe molecule. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic decolorization of Rhodamine B (RhB) aqueous solution at ambient temperature. The results indicate that the particle morphology, average crystallite size, specific surface areas, pore structures, and photocatalytic activity of the TiO2 samples can be readily controlled by changing the concentration of NH4HF2. With increasing NH4HF2 concentration, the average crystallite size and average pore size increase, whilst the specific surface area, pore volume and porosity steadily decrease. The photocatalytic activity of the as-prepared samples exceeds that of Degussa P25 (P25) when the molar ratios of fluorine to titanium (RF) are kept in the range of 0 to 1.