BiOI/Bi_2WO_6对甲基橙和苯酚的光催化降解及光催化机理(英文)

采用简单的沉积方法制备了不同碘化氧铋含量的BiOI/Bi2WO6光催化剂,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HR-TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和BET比表面积测量对其进行了表征。在紫外和可见光的照射下,使用甲基橙和苯酚的光催化降解评价了BiOI/Bi2WO6催化剂的光催化性能。结果表明:与商业P25和纯Bi2WO6相比,13.2%BiOI/Bi2WO6光催化剂具有更高的紫外和可见光催化性能。这明显增加的光催化活性主要归功于光生电子和空穴在Bi2WO6和BiOI界面上的有效转移,降低了电子-空穴对的复合。基于BiOI和Bi2WO6的能带结构,提出了光生载流子的一种转移过程。自由基清除剂的实验表明,·OH,h+,·O2-和H2O2,特别是h+,共同支配了甲基橙和苯酚的光催化降解过程。

Photocatalytic Degradation and Mechanism of BiOI/Bi2WO6 toward Methyl Orange and Phenol

BiOI/Bi₂WO₆ photocatalysts with various BiOIamounts were prepared by a simple deposition method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and low temperature nitrogen adsorption. The photocatalytic performance of BiOI/Bi₂WO₆ catalysts was evaluated using the photodegradation of methyl orange (MO) and phenol in an aqueous solution under UVand visible light irradiation. The results indicate that compared with commercial Degussa P25 and pure Bi₂WO₆, the 13.2% BiOI/Bi₂WO₆ photocatalyst shows much higher UVand visible light photocatalytic performance. The obviously increased photocatalytic activity could be mainly attributed to the effective transfer of the photogenerated electrons and holes at the interface of Bi₂WO₆ and BiOI, which reduces the recombination of electron-hole pairs. Atransfer process of photogenerated carriers is proposed based on the band structures of BiOIand Bi₂WO_6. Radical scavengers experiments demonstrate that ·OH, h⁺, ·O₂^-and H₂O₂, especially h⁺, together dominate the photodegradation process of MOand phenol.