Study of the effect of chemical composition on the surface wettability of three-dimensional graphene foams

Aminobenzene sulfonic acid (ABSA) was selected as a typical doping precursor for the preparation of N/S co-doped 3D graphene foam (SNGF). The effects of the position of -SO3H substituent group in ABSA and hydrothermal temperature on the surface wettability of SNGF have been studied. [Display omitted] The chemical composition obviously affects the surface wettability of a three-dimensional (3D) graphene material apart from its surface energy and microstructure. In the hydrothermal preparation, the heteroatom doping changes the chemical composition and wettability of the 3D graphene material. To realize the controllable surface wettability of graphene materials, aminobenzene sulfonic acid (ABSA) was selected as a typical doping agent for the preparation of nitrogen and sulfur co-doped 3D graphene foam (SNGF) using a hydrothermal method. Different from using o-ABSA or p-ABSA as the dopant, SNGF with tunable surface wettability is obtained only when m-ABSA is used. This result indicates that the substituent position of -SO3H group in the benzene ring of ABSA is rather important for the tunable wettability. This work provides some theoretical foundations for dopant selection and some new insights in manipulating the properties of 3D graphene foams by adjusting the configuration of dopants.