Mechanistic Study on Adsorption Desulfurization Using Modified Graphene

To enhance the adsorption desulfurization performance of graphene, graphene oxide was first hydrophobically modified by using dodecylamine and then reduced. Adsorption desulfurization experiments were performed on graphene with different degrees of reduction, where dibenzothiophene (DBT) was selected as thiophenic sulfur. FTIR, XRD, SEM, EDS, XPS, contact angle test, and elemental analysis showed that dodecylamine was successfully grafted onto a graphene surface, which could enhance the hydrophobic properties of graphene and effectively prevent the agglomeration of graphene sheets during the reduction process. Adsorption experiments showed that graphene with a higher degree of reduction had a larger DBT adsorption capacity. Density functional theory plus dispersion force correction calculation results showed that graphene with intact π-conjugated structure had the highest adsorption energy for DBT. Further population analysis showed that this π–π interaction was mainly caused by the dispersion force. The modification process can effectively recover the π-conjugated structure of graphene and enhance the π–π interaction with the thiophenic sulfur.