纳米微球NH2—Fe3O4@聚乙二醇@ZnO的制备及其光催化性能

Preparation and photocatalytic properties of NH2—Fe3O4@polyethylene glycol@ZnO nanospheres

首先合成氨基功能化Fe3O4(NH2—Fe3O4),并以NH2—Fe3O4为磁核,六水合硝酸锌(Zn(NO3)2·6H2O)为锌源,在表面活性剂聚乙二醇(PEG,PEG-400)辅助下通过水热法制备PEG修饰的ZnO(NH2—Fe3O4@PEG@ZnO)磁性复合材料。利用XRD、SEM、TEM、XPS、紫外-可见-近红外分光光度计、比表面吸附仪(BET)、振动样品磁强计(VSM)等对NH2—Fe3O4@PEG@ZnO复合材料组成、形貌、磁性能等进行表征。并进一步以罗丹明B(RhB)染料为模拟污染物,对NH2-Fe3O4@PEG@ZnO复合材料的光催化降解性能进行研究,采用单因素法探究Fe与Zn的原子比(n(Fe)∶n(Zn))、合成温度、表面活性剂种类及用量对NH2—Fe3O4@PEG@ZnO复合材料光催化降解性能的影响。结果表明,n(Fe)∶n(Zn)=1∶15、水热合成温度为180℃制备的NH2—Fe3O4@ZnO复合材料具有良好的光降解性能,0.0500 g NH2—Fe3O4@ZnO复合材料在紫外光照射20 min内对50 mL RhB(1.0×10-5 mol·L-1)溶液降解率为90.36%。而相同条件制备的NH2—Fe3O4@PEG@ZnO复合材料呈微球状,比表面积为11.43 m2·g-1,禁带宽度为2.51 eV,对RhB的光催化降解率可提高至99.36%,循环使用10次后,其对RhB的光催化降解率仍可达96.48%,PEG-400对NH2—Fe3O4@ZnO复合材料的光催化活性具有较大的协同效应。

The amino functionalized Fe3O4(NH2—Fe3O4)had been successfully prepared as magnetic core.With zinc nitrate hexahydrate(Zn(NO3)2·6H2O)as zinc source and polyethylene glycol(PEG,PEG-400)as surfactant,the magnetic composite based on zinc oxide and PEG-400-modified(NH2—Fe3O4@PEG@ZnO)composite was synthesized by hydrothermal process.The composition,morphology and magnetic properties of the NH2—Fe3O4@PEG@ZnO composite were characterized by a series of techniques including XRD,SEM,TEM,XPS,UV-VIS-NIR spectroscopy,specific surface area analyzer(BET),vibrating sample magnetometer(VSM)and so on.The photocatalytic performance of NH2—Fe3O4@PEG@ZnO composite under ultraviolet light was investigated by using the degradation of Rhodamine B(RhB)dye as a simulated pollutant.The influencing factors such as the atomic ratio of Fe to Zn(n(Fe)∶n(Zn)),reaction temperature,types and dosages of surfactant on photocatalytic degradation performance were investigated by one-factor method.The results show that NH2—Fe3O4@ZnO composite has good photocatalytic activity which is synthesized by n(Fe)∶n(Zn)is 1∶15 and the hydrothermal temperature is 180℃.The degradation rate of 50 mL RhB(1.0×10-5 mol·L-1)is 90.36%when use 0.0500 g NH2—Fe3O4@ZnO composite as a catalyst under ultraviolet light within 20 min.The specific surface area of NH2—Fe3O4@PEG@ZnO composite is 11.43 m2·g-1,the forbidden band width is about 2.51 eV and degradation rate of RhB is up to 99.36%.After 10 times of recycling,the photocatalytic degradation rate of RhB can still reach 96.48%.The combination of NH2-Fe3O4@ZnO composite and PEG-400 has a synergistic effect on improving the photocatalytic activity.