γ-Fe_2O_3纳米立方块修饰的Graphene/CdS复合光催化材料的合成及性能研究  

Synthesis of γ-Fe_2O_3 Nanocubes Decorated Graphene/CdS Nanocomposites with Enhanced Photocatalytic Performance

作　　者：吴佳佳[1] 季振源[1] 沈小平[1] 缪绪立 徐克强 

机构地区：[1]江苏大学化学化工学院,镇江212013

出　　处：《化学学报》2017年第12期1207-1214,共8页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.51272094;51602129);江苏省自然科学基金(Nos.BK20171295;BK20150507)资助~~

摘　　要：利用普鲁士蓝(PB)作为γ-Fe_2O_3前驱体,先依次在氧化石墨烯(GO)片上负载PB和CdS纳米粒子,再将其置于惰性气体(N2)氛围下进行煅烧,成功制备出CdS/RGO/γ-Fe_2O_3三元复合光催化剂.通过改变PB负载量可以得到不同γ-Fe_2O_3含量的三元光催化剂,且PB的方块状形貌在煅烧后得以保持.利用XRD、EDS、TEM、FT-IR、UV-vis等手段对所制备的样品进行组成、结构、形貌、光吸收等的分析表征,并以罗丹明B(Rh B)为模拟污染物研究上述催化剂对有机污染物的光催化降解性能.与二元复合物CdS/RGO相比,三元CdS/RGO/γ-Fe_2O_3光催化剂表现出更强的可见光催化活性,这说明γ-Fe_2O_3在光催化过程中起了重要作用.而且,由于γ-Fe_2O_3具有铁磁性,在外加磁场的作用下可以将光催化剂从反应体系中快速分离回收.同时,还研究了CdS/RGO/γ-Fe_2O_3光催化剂的降解动力学过程,并通过光催化剂的荧光表征和活性基团捕获实验,提出了光催化降解的机理.With Prussian blue （PB） as the precursor for γ-Fe2O3, the tri-component CdS/RGO/γ-Fe2O3 photocatalyst was prepared through loading PB nanocubes and CdS nanoparticles on graphene oxide （GO） nanosheets, followed by a calcina- tion process in inert atmosphere （N2）. The content of γ-Fe2O3 in the CdS/R60/γ-Fe2O3 photocatatyst can be adjusted by changing the loading mount of PB, and the cubic morphology of PB was maintained after the calcination. The composition, structure, morphology and light absorption of the as-prepared products were investigated by X-ray diffraction （XRD）, X-ray energy dispersive spectroscopy （EDS）, field emission scanning electron microscopy （SEM）, transmission electron microsco- py （TEM）, infrared spectroscopy （FT-IR）, Raman spectroscopy and ultraviolet-visible （UV-vis） spectroscopy. The photocata- lytic activity of the ternary photocatalysts was evaluated by the degradation of the orgahic pollutant of Rhodamine B （RhB） under visible-light irradiation. It was found that the degradation process of RhB follows pseudo-first-order kinetics. Com- pared to the bi-component CdS/RGO photocatalyst, the tri-component CdS/RGO/γ-Fe2O3 exhibited greatly enhanced photo- catalytic activity, demonstrating that the γ-Fe2O3 played an important role in the photocatalytic process. The CdS/RGO/γ-Fe2O3 composite with PB loading amount of 12 mg exhibits the highest photocatalytic degradation efficiency of about 99.8% and the highest apparent reaction rate constant （k） value of about 0.03289 rain-l, which is almost 2.9 times and 1.8 times higher than that of CdS and CdS/RGO, respectively. This result indicates that a suitable loading amount of γ-Fe2O3 is important to optimize the photocatalytic performance of the CdS/RGO/γ-Fe2O3 composites. Moreover, owing to the ferro- magnetism of γ-Fe2O3, the CdS/RGO/γ-Fe2O3 photocatalyst could be easily separated from the reaction solution for recycling by a magnet. A possible photocatalytic mechanism was also proposed based on

关 键 词：Γ-FE2O3 石墨烯 CDS 光催化 机理 

分 类 号：O643.36[理学—物理化学]