Bi2S3@BiOBr的原位合成及其可见光催化性能

In-situ synthesis and visible-light-driven photocatalytic activity of Bi2S3@BiOBr

采用溶剂热法合成BiOBr空心微球,并利用简单的离子交换原位生成Bi2S3,得到类核-壳结构的Bi2S3@BiOBr复合光催化剂。利用X射线衍射(XRD)、扫描电子显微镜(FE-SEM)和紫外-可见漫反射光谱(UV-Vis DRS)等手段对催化剂进行表征,并对其进行光电化学性能测试。实验表明,BiOBr与Bi2S3形成的异质结促进了光生载流子的转移和分离。Bi2S3@BiOBr在可见光作用下可以有效降解甲基橙,当Bi2S3的摩尔分数为8%时,样品具有最好的光催化性能。·O2-和h+是Bi2S3@BiOBr光催化降解甲基橙的主要活性物种。

Bi2S3@BiOBr core-shell structure was obtained by a facile anion exchange process to form Bi2S3 in situ on the surface of BiOBr hollow microspheres, which were firstly prepared by a one-step solvothermal method. The crystal structure, morphology and photo-absorption property of the obtained samples were characterized by X-ray diffraction(XRD), field-emission scanning electron microscopy(FE-SEM), UV-Vis diffuse reflectance spectroscopy(DRS), etc. The photoelectrochemical property of the samples was also measured. The results showed that the intimate heterojunction between BiOBr and Bi2S3 greatly promoted the separation of charge carriers, resulting in the superior visible-light-driven photocatalytic activity for the degradation of methyl orange(MO). The sample containing 8% Bi2S3 exhibited the best photocatalytic performance. The radical trapping experiments demonstrated that ·O2- and h+ played decisive roles in the photo-degradation of MO.