Fabrication of rGO/g-C3N4 composites: Via electrostatic assembly towards charge separation control

Abstract

Herein, g-C3N4 nanosheets (NSs) were grown on reduced graphene oxide (rGO) using cross linking molecules by an electrostatic assembly process from carboxyl and amine groups via π-π stacking interaction to fabricate heterostructures. Detailed characterizations such as Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electronmicroscopy, photoelectrochemical measurements, X-ray photoelectron spectroscopy, and photoluminescence (PL) spectroscopy demonstrated step-by-step immobilization of 1-pyrene carboxylic acid, polyaniline (PANI), and g-C3N4 on rGO. The π-π stacking plays an important role for the formation of rGO/g-C3N4 composites. The surface of rGO was homogeneously decorated with monodispersed g-C3N4 NSs. The resulting rGO/g-C3N4 composites obtained endowed the heterostructures with novel functions. Both the rGO-COOH/g-C3N4 and rGO-PANI/g-C3N4 composites revealed enhanced conduction properties. Absorption and PL spectra of the composite samples confirmed the attachment of g-C3N4 on rGO. Due to the presence of carboxyl groups on 1-pyrene carboxylic acid, rGO-COOH/g-C3N4 composites demonstrated enhanced photocatalysis properties.