BiOBr/BiVO_4异质结薄膜的制备及其光催化性能研究

Study of Synthesis and Photocatalytic Properties of BiOBr/BiVO_4 Heterojunction Films

通过浸渍法在普通玻璃上制备了纯BiVO_4薄膜和BiOBr/BiVO_4异质结薄膜,运用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对其晶体结构及形貌进行表征.薄膜光催化剂的XRD图谱显示:纯BiVO_4薄膜为单斜白钨矿结构,BiVO_4与BiOBr复合后,BiVO_4的晶体结构未发生改变,BiOBr为四方氟氯铅矿型,且均具有较高的结晶度和纯度.在模拟太阳光的辐射下,以亚甲基蓝染料为目标污染物,对薄膜光催化剂的光催化性能进行评价.光催化降解结果表明,在光下照射3 h后,纯BiVO_4和BiOBr/BiVO_4异质结薄膜对亚甲基蓝的光催化降解率分别为63.33%和85.14%.与纯BiVO_4薄膜相比,BiOBr/BiVO_4异质结薄膜具有更高的光催化性能.

The pure BiVO4 film and BiOBr/BiVO4 heterojunction films on glass substrate have been synthesized by impregnation method. X-ray diffraction （XRD） and scanning electron microscopy （SEM） are used to characterize the crystal structure and morphology of the film photocatalysts. The XRD patterns of the film photocatalysts indicate that the crystal structure of BiVO4 is still monoclinic scheelite type after construction of BiVO4 based composite with BiOBr, and BiOBr is tetragonal matlockite type. Moreover, the samples have high crystallinity and purity. The photo- catalytic performance of the film photocatalysts are evaluated for degradation of methylene blue （MB） under simulated sunlight irradiation. The results of photocatalytic degradation show that under light irradiation after 3 h, the pho- tocatalytic degradation rate of pure BiVO, film and BiOBr/BiVO4 heterojunction film for MB is 63.33% and 85.14%, respectively. Compared with pure BiVO4 films, the BiOBr/BiVO4 heterojunction film exhibits a higher photocatalytic performance.