The purpose of this study is to investigate the influence of Cu on TiO₂ phase transformation and regioselectivity. TiO₂ samples doped with different amounts of Cu²⁺ ions were synthesized by the sol-gel method. The phase and vibrational mode were characterized by X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR), and transmission electron microscope (TEM). The XRD phase analysis shows that the lattice parameters have not changed after Cu incorporation. In addition, the content of rutile increased obviously after Cu doping. This indicated that the addition of Cu obviously promoted the transformation from anatase phase to rutile phase. The vibration frequencies were calculated based on the principle of electronegativity. All types of bonds were qualitatively and quantitatively analyzed. The content of Ti_A-O, Ti_R-O, and H-O in the undoped TiO₂ samples is 23.87%, 16.30%, and 7.41%, respectively. In the same way, the content of Ti_A-O, Ti_R-O, H-O, -O, and -O in the 2.5 mol%Cu-doped TiO₂ samples is 21.23%, 18.56%, 7.34%, and 0.98%, respectively. For the 5 mol%Cu-doped TiO₂ samples, the content of Ti_A-O, Ti_R-O, H-O, -O, -O, -O, and -O is 18.75%, 20.11%, 7.47%, 2.56%, 3.9%, 1.55%, and 2.35%, respectively. Cu was not present at substitutional sites in the 2.5 mol% doped sample, but Cu was present in the 2.5 mol% doped sample. It is indicated that Cu was more likely to exist in the form of interstitial position in the TiO₂ lattice, with the number of Cu atoms in the interstitial position reaching saturation, and this forced Cu to replace Ti. The TEM shows that the stripes of different periods and orientations overlapped each other to form the Moiré patterns. In addition, the diffraction patterns of the Moiré image were slightly different from that of the matrix. The Cu replaced Ti position and the Cu atoms mixed into interstitial sites in the TiO₂ lattice. The theoretical calculation was consistent with the experimental results.

中文翻译：

---

电负性原理定量计算的Cu掺杂TiO2价键的振动光谱

这项研究的目的是研究铜对TiO ₂相变和区域选择性的影响。TiO ₂样品掺杂了不同量的Cu ²⁺离子通过溶胶-凝胶法合成。通过X射线衍射（XRD），傅立叶红外光谱（FTIR）和透射电子显微镜（TEM）表征了相和振动模式。XRD相分析表明，加入Cu后晶格参数没有改变。另外，铜掺杂后金红石含量明显增加。这表明Cu的添加明显促进了锐钛矿相向金红石相的转变。根据电负性原理计算振动频率。定性和定量分析了所有类型的键。未掺杂的TiO ₂中Ti _A -O，Ti _R -O和HO的含量样本分别为23.87％，16.30％和7.41％。以相同的方式，将Ti的含量_甲-O，钛_{- [R} -O，HO，- O，和- 2.5摩尔％的Cu掺杂TiO为O ₂的样品是21.23％，18.56％，7.34％，和0.98％ ， 分别。为5摩尔％的Cu掺杂TiO _2米的样品，Ti的含量_甲-O，钛_{- [R} -O，HO，- O，- O，- O，和-O分别为18.75％，20.11％，7.47％，2.56％，3.9％，1.55％和2.35％。在2.5mol％掺杂的样品中Cu不存在于取代位点，但是在2.5mol％掺杂的样品中Cu存在。可以看出，在TiO ₂晶格中，Cu更可能以间隙位置的形式存在，间隙位置中的Cu原子数达到饱和，这迫使Cu替代Ti。TEM显示，不同周期和取向的条纹彼此重叠以形成莫尔条纹。此外，莫尔像的衍射图与​​基体的衍射图略有不同。Cu取代了Ti的位置，并且Cu原子混入了TiO ₂中的间隙位置格子。理论计算与实验结果吻合。