可磁分离Fe_3O_4/g-C_3N_4复合材料的制备及其性能

Preparation and properties of magnetic separation Fe_3O_4/g-C_3N_4 composites

为了利用Fe_3O_4的磁响应性及石墨相C_3N_4(g-C_3N_4)优良的光催化活性,首先采用高温热聚合法,以尿素为前驱体制备g-C_3N_4,然后采用水热法合成了可磁分离Fe_3O_4/g-C_3N_4复合材料。利用TEM、XRD、TGA、BET和振动样品磁强计(VSM)等多种测试手段表征分析Fe_3O_4/g-C_3N_4复合材料的形貌、晶型结构、比表面积、成分、饱和磁化强度等。通过模拟太阳光下Fe_3O_4/g-C_3N_4复合材料光催化吸附降解亚甲基蓝(MB)的实验,评价了Fe_3O_4/g-C_3N_4复合材料的吸附性能及光催化性能。结果表明,可磁分离Fe_3O_4/g-C_3N_4复合材料具有较大的比表面积,约为71.89m2/g;且具有较好的磁性,饱和磁化强度为18.79emu/g,可实现复合材料的分离回收;光照240min时,Fe_3O_4/g-C_3N_4复合材料对MB的去除率为56.54%。所制备的Fe_3O_4/g-C_3N_4复合材料具有优良的吸附性能、光催化活性和磁性,并可通过外加磁场进行分离与回收。

In order to utilize the magnetic responsiveness of Fe3O4 and the excellent photocatalytic activity of graphite carbon nitride（g-C3N4）,high temperature thermal polymerization method was used to prepare g-C3N4 with urea as a precursor.The magnetic separation Fe3O4/g-C3N4 composite photocatalyst was synthesized by hydrothermal method.The obtained samples were characterized by TEM,XRD,TGA,BET and vibrating sample magnetometer（VSM）to investigate the morphology,crystalline phase,specific surface area,composition and saturation magnetization of Fe3O4/g-C3N4 composites.The adsorption and photocatalytic properties of Fe3O4/g-C3N4 composites were evaluated by the adsorption and photocatalytic degradation of dye methylene blue（MB）under simulated sunlight.The results show that the specific surface area of magnetic separation Fe3O4/g-C3N4 composites is large compared with g-C3N4,up to 71.89 m2/g.Fe3O4/g-C3N4 composites possess good magnetic,and the intensity of saturation magnetic field reaches to 18.79 emu/g,which is enough for magnetic separation and recovery.The removal rate of MB reaches to 56.54% under irradiation for 240 min.Fe3O4/g-C3N4 composites not only exhibit good adsorption and photocatalytic activity and magnetic,but also can be recovered easily by external magnetic field.