石墨烯基分子印迹气凝胶制备及吸附性能研究

Preparation and adsorption properties of graphene-based molecularly imprinted aerogels

以氧化石墨烯(GO)为分子骨架,负载纳米氧化铁(γ-Fe2O3)和TiO2赋予GO磁性和光催化性;利用苯并α芘(BaP)为模板合成具有识别吸附降解BaP性能的石墨烯基分子印迹气凝胶(GMIA)。通过傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和X射线能谱(EDS)表征中间及最终产物;气相色谱-气质联用仪(GC-MS)分析GMIA富集识别BaP性能及降解功效,探究GMIA对BaP的吸附动力学并分析吸附机理与降解机制。结果表明:GMIA能高效分子识别BaP,平衡吸附量为236.891 ng·g^(-1),识别的印迹因子α=2.35,选择性明显优于石墨烯基非分子印迹气凝胶(GNMIA),GMIA对BaP的吸附行为符合二级动力学吸附模型。紫外照射GMIA即可完全降解BaP,与GNMIA相比具有显著的光催化降解性能。同时,GMIA吸附脱附处理后的重复利用性能良好。

Nano-iron oxide(γ-Fe2O3)and TiO2 were loaded onto graphene oxide(GO)as molecular skeleton for magnetic and photocatalytic properties,and benzo[α]pyrene(BaP)was used as a template to synthesize gaphene-based molecularly imprinted aerogel(GMIA)with the ability of recognizing and degrading BaP.Intermediates and final products were characterized by Fourier infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray energy spectroscopy(EDS).Gas chromatography together with gas chromatography-mass spectrometry(GC-MS)was used to analysis GMIA enrichment and BaP recognition and degradation efficiency,and the adsorption kinetics,adsorption mechanism and degradation mechanism were analyzed.The results show that GMIA efficiently recognizes BaP with equilibrium adsorption capacity of 236.891 ng·g^(-1).The recognized imprinting factorα=2.35 is much higher than that of graphene-based non-molecularly imprinted aerogel(GNMIA).The adsorption behavior follows to the second-order kinetic adsorption model.Compared with GNMIA Ultraviolet radiation,GMIA has remarkable degradation property for complete BaP degradation.Moreover,it has better recycling performance after adsorption-desorption treatments.