SiO_(2)@ZIF-67基复合材料对甲基橙的低温吸附性能研究

Study on the low-temperature adsorption performance of SiO_(2)@ZIF-67-based composites for methyl orange

吸附法是处理有机废水技术中最简单而有效的方法,但在低温(低于10℃)时,材料的吸附性能急剧下降。通过在SiO_(2)@ZIF-67中引入氧化石墨烯(GO)、碳纳米管(CNTs)、二硫化钼(MoS_(2))制备了SiO_(2)@ZIF-67基复合材料(SiO_(2)@ZIF-67/GO、SiO_(2)@ZIF-67/CNTs、SiO_(2)@ZIF-67/MoS_(2)),并对其进行高温煅烧处理。采用X射线衍射仪、扫描电子显微镜以及氮气吸附-脱附等手段对材料结构进行表征,并研究其在低温环境下对甲基橙的吸附性能。结果表明:煅烧后复合材料以介孔结构为主,表现出优异的吸附性能,其中SiO_(2)@ZIF-67/GO(S)的比表面积可达303m^(2)/g,在5℃条件下对质量浓度100mg/L甲基橙溶液的最大饱和吸附量为332mg/g,饱和吸附量分别是SiO_(2)@ZIF-67/GO、活性炭的2.9倍和4.4倍;复合材料的吸附过程符合Freundlich模型和准一级动力学模型,吸附以物理吸附为主。

Adsorption is the simplest and most effective method in organic wastewater treatment technology,but the adsorption performance of materials decreases dramatically at low temperatures(below 10℃).A series of SiO_(2)@ZIF-67-based composites(SiO_(2)@ZIF-67/GO,SiO_(2)@ZIF-67/CNTs,SiO_(2)@ZIF-67/MoS_(2))were prepared by introducing graphene oxide(GO),carbon nanotubes(CNTs)and molybdenum disulfide(MoS_(2))in SiO_(2)@ZIF-67,and subjected to high-temperatures calcination.The structure of the composites was characterized by XRD,SEM,and nitrogen adsorption-desorption,and their adsorption properties for methyl orange at low temperature were studied.The results showed that after calcination,the composites were predominantly mesoporous structure and exhibited excellent adsorption properties.The specific surface area of SiO_(2)@ZIF-67/GO(S)could reach 303m^(2)/g,and its maximum saturation adsorption capacity for 100mg/L methyl orange solution at 5℃was 332 mg/g,which was 2.9 and 4.4 times that of SiO_(2)@ZIF-67/GO and activated carbon,respectively.The adsorption process of the composites was in accordance with the Freundlich model and the quasi-first order kinetic model,with physical adsorption dominating.