Phenyl sulfonic acid functionalized graphene-based materials: Synthetic approaches and applications in organic reactions

Catalysts are one of the essential elements in the synthesis of organic chemicals. Easily recoverable and reusable catalysts with facile preparation methods are highly demanded for production of desired chemicals with higher yields in industry. Special attention has been devoted to solid acid catalysts based on graphene oxide (GO) or reduced graphene oxide (rGO) in recent years. Despite some attempts made on the manufacturing various kinds of graphene-based acid catalysts, herein, we aim to take a closer look on the surface functionalization of graphene materials with a certain type of acidifying reagent i.e. sulfanilic acid. This review provides information associated with all of the synthesis routes of phenyl sulfonic acid functionalized graphene-based nanomaterials and their utilization in producing fine chemicals through the acid-catalyzed organic transformations. [Display omitted] •Graphene based solid acid catalysts have been used to catalyze numerous organic reactions so far.•Sulfanilic acid was found as extensively used benign sulfonating reagent on graphene surface.•This review shows the importance of using Ph-SO3H graphene materials in various organic reactions.•All preparation techniques to achieve PhSO3H-graphene materials are discussed in details.•The superiority and inferiority of intended catalysts are demonstrated in each organic reaction.