石墨烯/SiO_2气凝胶对苯、甲苯水溶液的吸附

Adsorption of benzene and toluene from aqueous solutions onto composite graphene/SiO_2 aerogel

以正硅酸乙酯(TEOS)与氧化石墨烯(GO)为原料,采用溶胶–凝胶法,经表面改性、常压干燥制备不同GO含量的氧化石墨烯/二氧化硅气凝胶(GOS),再由高温还原得到石墨烯/二氧化硅气凝胶(GS).通过堆密度、比表面积等测试,将最佳配比的GS与活性炭(AC)、SiO_2气凝胶作对比,研究其对苯和甲苯溶液的吸附性能,并探讨了GS的吸附机理.结果表明:掺杂3%GO的复合气凝胶性能有显著提升.松散堆密度为160kg/m^3,比表面积、孔径分别为1039m^2/g、16.56nm,对苯、甲苯水溶液的最大饱和吸附量分别达到180mg/g,210mg/g,约为活性炭吸附量的2.5倍.且吸附过程符合Langmuir等温吸附模型.

This paper used tetraethoxysilane（TEOS） and graphene oxide（GO） as the raw materials.Graphene/silica aerogels（GS） with different content of GO were synthesized via sol-gel method, combined with surface modification, ambient drying process and high temperature reduction. Through the consider of the density and the specific surface area, the best GS was obtained and the adsorption of benzene and toluene solution was studied compared with the activated carbon and SiO_2 aerogel. The results show that the specific surface area of the silica gel is improved greatly by the addition of 3% GO, which made the porous and homogeneous structure. The density is 160kg/m^3, the specific surface area and pore diameter are 1039m^2/g and 16.56 nm, respectively. The adsorption of benzene and toluene reaches 180mg/g and 210mg/g, respectively. They are approximately 2.5 times of the amount of activated carbon adsorption. The adsorption process was in accordance with the Langmuir isotherm model.