Anatase TiO₂ samples were synthesized in the presence of different amounts of HF acid with the aim of understanding the effect of the presence of fluorine on the photocatalytic activity. It is well known that the presence of fluoride ions influences the photocatalytic performance by adsorption on the surface of TiO₂ and that they are capping agents in the control of specific exposed facets. The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, nitrogen adsorption–desorption measurements, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectrophotometry, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was evaluated in gas–solid and liquid–solid systems by monitoring the oxidation of 2-propanol and 4-methoxybenzyl alcohol, respectively. Some differences in the physico-chemical properties of the different samples were noted; in particular, the presence of F⁻ caused a net decrease of the specific surface area, an increase of the crystallinity degree and an increase of the conductivity, whilst only a slight difference was noted in the distribution of the exposed anatase facets. Moreover, an increase in the total oxidation of 2-propanol and in the selectivity to 4-methoxybenzaldehyde was observed.

中文翻译：

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氟对用于光催化部分氧化的锐钛矿型TiO ₂合成的影响：暴露的小面是主要作用者吗？†

为了理解氟的存在对光催化活性的影响，在不同量的HF酸存在下合成了锐钛矿型TiO ₂样品。众所周知，氟离子的存在通过吸附在TiO ₂的表面上而影响光催化性能。并且它们是控制特定暴露面的封闭剂。通过X射线衍射（XRD），拉曼光谱，氮吸附-解吸测量，扫描电子显微镜（SEM），透射电子显微镜（TEM），紫外可见分光光度法和X射线光电子能谱（XPS）对样品进行了表征。通过分别监测2-丙醇和4-甲氧基苄醇的氧化，在气-固和液-固体系中评估了光催化活性。注意到不同样品的理化性质存在一些差异。特别是，F的存在^-导致比表面积的净减少，结晶度的增加和电导率的增加，而暴露的锐钛矿小面的分布仅观察到细微的差异。此外，观察到2-丙醇的总氧化和对4-甲氧基苯甲醛的选择性的增加。