Engineering Surface Wettability of Reduced Graphene Oxide To Realize Efficient Interfacial Photocatalytic Benzene Hydroxylation in Water

Selective one-step benzene hydroxylation to produce phenol is a green process, especially when the reaction can be carried out in water using economical carbon materials as catalysts under visible light. Herein, we reported that hydroxylation of benzene can be realized over reduced graphene oxide (RGO) in water under visible light using H2O2 as an oxidant. By engineering the surface wettability of RGO from hydrophilic (with a contact angle of 52 degrees) to hydrophobic (with a contact angle of 127 degrees), the performance for benzene hydroxylation can be significantly improved by more than three times. An optimum conversion of benzene reached 3.1% with a H2O2/benzene ratio of 1:1 over hydrophobic RGO after irradiation for 20 h. The catalyst can be facilely recycled, and no obvious decrease in the activity was observed after four successive runs. This study provides a green and sustainable method for phenol production based on economical carbon materials and also highlights the important role of RGO as a promising photocatalyst for organic syntheses.