石墨烯气凝胶的制备与模拟染料废水的脱色

采用改进Hummers法制备了氧化石墨,利用超声波机械剥离获得了氧化石墨烯(GO),在此基础上通过水热还原反应制备出还原GO的水凝胶,再利用冷冻干燥方式制备了石墨烯气凝胶(GA)。在对制备条件进行优化的基础上,采用XRD,SEM,Raman,AFM和BET等设备和手段对获得的GA进行了结构特性表征。通过考察对亚甲基蓝模拟染料废水吸附处理效果,研究了三维GA对模拟染料废水的吸附处理性能。研究表明,在180℃下,采用水热还原法反应12 h制备石墨烯水凝胶,获得了稳定的石墨烯水凝胶三维块体结构;在300 Pa、-20℃条件下冷冻干燥12 h,获得表面呈泡沫状多孔三维结构、内部呈花瓣样结构的GA块体;其比表面积为1742.48 m^(2)/g;作为吸附剂处理浓度为20 mg/L的亚甲基蓝模拟染料废水,脱色率可达98%以上。

Graphite oxide was prepared by modified Hummers method.Graphene oxide(GO)was obtained by ultrasonic mechanical exfoliation,accordingly a hydrogel of reduced GO was prepared through hydrothermal reduction,and then graphene aerogel(GA)was produced by freeze drying.After adjusting the optimal parameters,the best preparation conditions were defined.The structural properties of the obtained GA were characterized by XRD,SEM,Raman,AFM and BET.On this basis,the synthetic dye wastewater by using methylene blue served as the object to observe the adsorption effect of three-dimensional GA on synthetic dye wastewater.The results showed that the optimal hydrothermal temperature was 180℃and the optimal reaction time was 12 h for preparing graphene hydrogel,under this condition,a stable graphene hydrogel with three-dimensional block structure was obtained by hydrothermal reduction.Furthermore,after freeze-drying at-20℃,300 Pa vacuum for 12 h,GA block with a foam-like porous three-dimensional structure on the surface and a petal-like structure inside was obtained.The results showed that,the specific surface area of the obtained GA was 1742.48 m^(2)/g;the obtained GA as the adsorbent to treat methylene blue synthetic simulated dye wastewater with a concentration of 20 mg/L,the decolorization rate could be up to 98%.