Phase engineering in graphitic carbon nitride with imidazolium sulfonic acid chloride ionic liquid functionalization for photocatalytic side-chain oxidation of toluene

Herein, the phase and photocatalytic property of graphitic carbon nitride (g-C 3 N 4 ) are modulated with the functionalization of ionic liquid (IL) by post-treatment of g-C 3 N 4 with imidazolium sulfonic acid chloride. The structure, morphology and optoelectronic properties of synthesized catalyst were thoroughly investigated. The functionalization of Ionic liquid has induced polycrystallinity to the amorphous g-C 3 N 4 . The g-C 3 N 4 –IL is highly efficient towards photocatalytic side-chain oxidation of toluene using H 2 O 2 with toluene conversion of 58% with 97% benzaldehyde selectivity in acetonitrile and toluene conversion of 49% and 96% benzaldehyde selectivity in organic solvent-free conditions. The synergy between g-C 3 N 4 and the IL elevates the visible light absorption and lower photoluminescence intensity. The g-C 3 N 4 -IL catalyst efficiently halts over-oxidation to get high selectivity for the desired product. In addition, graphene oxide and reduced graphene oxide were also functionalized with IL to examine their photocatalytic efficiency and considerable efficiencies were observed. The g-C 3 N 4 -IL is highly stable and recyclable. • The g-C 3 N 4 –IL was synthesized by post-treatment of g-C 3 N 4 with imidazolium sulfonic acid chloride. • IL functionalization induces polycrystallinity in g-C 3 N 4 –IL as shown in ED and Raman spectra. • The photocatalytic efficiency was examined with side-chain oxidation of toluene. • The catalyst was highly stable and recyclable.