Adsorption of clofibric acid and naproxen on graphene oxide modified SBA-15

Abstract

The purposes in this study are to synthesize and characterize graphene oxide (GO) modified on mesoporous silica (SBA-15), to study the adsorptive information of clofibric (CFA) and naproxen (NAP) on GO modified SBA-15 by batch experiment, and to investigate selective adsorption of CFA and NAP on GO modified SBA-15. In this study, SBA-15, GO and GO modified SBA-15 were synthesized and functionalized with amine functional group to investigate the effect of amine functional group on adsorption capacity and mechanism. GO modification on SBA-15 can increase the CFA and NAP adsorption capacity. Amine functional group on both SBA-15 and GO can decrease adsorption rate of CFA and NAP. But, the amine functional group can increase the adsorption capacities of CFA but did not change significantly for NAP. CFA and NAP adsorption capacities on GO modified SBA-15 were more favor with acidic condition as pH 5 but decreased in higher pH. Electrostatic attraction can be concluded as an important adsorption mechanism. In addition, adsorption isotherms of CFA and NAP in low concentration (ppb level) were studied and compatible with Linear and Langmuir isotherm, respectively. Form adsorption selectivity, it can be confirmed that amine functional group showed the favor for CFA adsorption. And the adsorption of NAP was easily disturbed by CFA on GO modified SBA-15.