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.