具有不同Bi/Ti摩尔比的BiOI/TiO_2(A)光催化剂的结构与性能(英文)

Structure and Properties of BiOI/TiO_2(A) Photocatalysts with Different Bi/Ti Molar Ratios

在室温条件下通过沉积法制备了BiOI敏化纳米锐钛矿TiO2(A)光催化剂. 用 X 射线衍射(XRD), X 射线光电子能谱(XPS), 光致发光(PL)光谱和紫外-可见漫反射光谱(UV-Vis DRS)等手段对其进行了表征. 通过罗丹明B(RhB)催化降解实验评价了其光催化活性. 随BiOI含量增加, BiOI/TiO2(A)在 370-630nm的吸收强度增强, 吸收带边红移增加, 紫外和可见光催化活性先增加, 当Bi/Ti摩尔比约为1.7%时, 各自达到最大值, 然后随BiOI 含量的进一步增加而减小. 1.7% BiOI/TiO2(A)的可见光活性明显高于P25, 它的紫外光活性也略高于P25. 在BiOI含量相近时, BiOI/TiO2(A)比 BiOI/P25 具有更低的光催化活性. 和TiO2(A)相比,1.7% BiOI/TiO2(A)明显具有更高的紫外和可见光催化活性, 这归因于它在370-630nm的强吸收、吸收带边红移明显以及光生电子和空穴的有效转移, 减少了电子-空穴对的复合.

BiOI-sensitized nano-anatase （TiO2 （A）） photocatalysts were prepared by a deposition method at room temperature, and characterized by X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and photoluminescence （PL）, and UV-Vis diffuse reflectance spectra （UV-Vis DRS）. The photocatalytic activities were evaluated by photo-degradation experiments of rhodamine B. With increasing BiOI content, the absorption intensity of BiOI/TiO2 （A） increases in the 370-630 nm region and the absorption band edge redshifts. The UV and visible light photocatalytic activities increase, reaching a maximum when the Bi/Ti molar ratio is 1.7% . The 1.7% BiOI/TiO2 （A） catalyst exhibits much higher visible-light photoactivity than P25, and its UV-light photoactivity is slightly higher than that of P25. The UV and visible light photocatalytic activities of BiOI/TiO2 （A） with similar BiOI content are lower than those of BiOI/P25 catalysts. Compared with TiO2 （A）, 1.7% BiOI/TiO2 （A） shows higher UV and visible light photoactivities. This is attributed to the strong absorption in the 370-630 nm region, the redshift of the absorption band edge, and the effective transfer of the photogenerated electrons and holes, which reduces the recombination of electron-hole pairs.