论文部分内容阅读
以改进的Hummers法制备的氧化石墨烯为原料,采用共沉淀法获得磁性的石墨烯-Fe_3O_4载体,进而采用水热法制备出TiO_2/石墨烯-Fe_3O_4磁性三元复合光催化剂。借助X射线衍射(XRD)、扫描电子显微镜(SEM)及固体紫外-可见漫反射光谱(UV-vis DRS)对产物进行表征,并通过在紫外光和可见光下对亚甲基蓝的降解来评价复合光催化剂的催化性能及稳定性能。结果表明,Ti O_2/石墨烯-Fe_3O_4磁性三元复合光催化剂对亚甲基蓝的光催化降解符合拟一级动力学模型。该复合催化剂在紫外光和可见光下均具有较好的光催化性能,且催化活性均高于纯Ti O_2。石墨烯由于担当了载体和电子受体,增强了Ti O_2在可见光区域的吸收,能有效提高对目标污染物的光催化降解活性,同时通过添加磁性Fe_3O_4,进一步提高了其回收再利用性。
The improved graphene oxide prepared by Hummers method was used as raw material, and the magnetic graphene-Fe 3 O 4 carrier was obtained by coprecipitation method. Then the TiO 2 / graphene-Fe 3 O 4 magnetic ternary photocatalyst was prepared by hydrothermal method. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and solid-state UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and the composite photocatalyst was evaluated by degradation of methylene blue under UV light and visible light The catalytic performance and stability. The results showed that the photocatalytic degradation of methylene blue by Ti O 2 / graphene-Fe 3 O 4 magnetic ternary composite photocatalyst fit the first-order kinetic model. The composite catalyst has good photocatalytic activity under ultraviolet light and visible light, and the catalytic activity is higher than that of pure TiO2. Graphene, which acts as a carrier and an electron acceptor, enhances the absorption of Ti O 2 in the visible region and effectively improves the photocatalytic degradation activity of the target pollutants. Meanwhile, the addition of magnetic Fe 3 O 4 improves the recycling of graphene.