Graphene oxide and graphitic carbon nitride nanocomposites assembled by electrostatic attraction forces: Synthesis and characterization

Abstract

Photocatalytically active nanocomposites based on exfoliated at 550 degrees C graphitic carbon nitride nanosheets (NS) modified by graphene oxide (GO) were synthesized taking the advantage of electrostatic attraction forces originating between oppositely charged NS and GO nanosheets. The process was based on mixing of aqueous suspensions of GO and NS, both having pH = 3, with the aim to set the negative surface charge to GO and positive charge to NS. High resolution scanning electron microscopy (HRSEM) and S/TEM with elemental mapping revealed that GO was surrounded by exfoliated carbon nitride and thus large number of heterojunctions was created. Photoluminescence spectroscopy (PL) confirmed that the separation efficiency of photogenerated electrons and holes was more intense in GO/NS. Photocatalysis was used as a characterization method and indicated created heterojunction between GO and NS. The improved GO/NS photocatalytic degradation activity against the indigo carmine (IC) dye was observed as a result of higher production of superoxide radicals.