由钛铁矿合成磁性氧化钛纳米片基光催化剂 Magnetically Separable Titania Nanosheets Based Photocatalyst from Ilmenite

以钛铁矿为原料，通过浓盐酸浸出法提取了其中的氧化钛和氧化铁，浸出率高达~97%，氧化钛和氧化铁的收率分别为~53%和~80%。并以氧化铁为原料合成了Fe3O4@SiO2磁核，通过固相合成及软化学剥离制备了二维氧化钛纳米片(TNSs)溶胶，并进一步制备了可磁分离的Fe3O4@SiO2@TNSs复合材料。以可见光或太阳光为光源，催化剂在H2O2辅助下表现出优异的活性，其降解RhB的速率常数分别是商品氧化钛P25以及Fe3O4/N-TiO2光催化剂的14.5倍和20.4倍。此外，相比于P25纳米氧化钛的难以回收，合成的Fe3O4@SiO2@TNSs催化剂在外磁场作用下实现快速回收。催化剂表现出极佳的稳定性和循环性，五次重复使用后仍能几乎完全降解有机污染物。 TiO2 and Fe2O3 were extracted from ilmenite using a HCl treating method, in which the conversion ratio of ilmenite was ~97% and the yields of TiO2 and Fe2O3 were respectively ~ 53% and ~80%. With the prepared Fe2O3 as the precursor, we synthesized the magnetic core of Fe3O4@SiO2, and fur-ther fabricated the magnetically separable Fe3O4@SiO2@ titania nanosheets (TNSs) composite by using the two-dimensional TNSs from the solid reaction and the followed soft-chemistry exfoliation. This composite exhibited superior photocatalytic performance with the H2O2 assistance under visible light or sun light irradiation, and its rate constant for degradation of Rhodamine B was respectively 14.5 and 20.4 times higher than those of Degussa P25 TiO2 and Fe3O4/N-TiO2 samples. Moreover, in comparison to the recycling difficulty of P25 TiO2, the prepared Fe3O4@SiO2@TNSs composite could be easily recovered by the external magnet. This composite also exhibited the excellent stability and reusability, and after 5 successive cycles the dye molecules still could be decomposed.