Enhanced photochemical oxidation ability of carbon nitride by π–π stacking interactions with graphene

Abstract

A one-pot method for the preparation of g-C3N4/reduced graphene oxide (rGO) composite photocatalysts with controllable band structures is presented. The photocatalysts are characterized by Fouirer transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope, and Mott-Schottky analysis. The valance band (VB) of g-C3N4 exhibits a noticeable positive shift upon hybridizing with rGO, and thus results in a strong photo-oxidation ability. The g-C3N4/rGO composites show a higher photodegradation activity for 2,4-dichlorophenol (2,4-DCP) and rhodamine B (RhB) under visible light irradiation (λ≥420 nm). The g-C3N4/rGO-1 sample exhibits the highest photocatalytic activity, which is 1.49 and 1.52 times higher than that of bulk g-C3N4 for 2,4-DCP and 1.52 times degradation, respectively. The enhanced photocatalytic activity for g-C3N4 originates from the improved visible light usage, enhanced electronic conductivity and photo-oxidation ability by the formed strong π-π stacking interactions with rGO.