Facile hydrothermal preparation of graphitic carbon nitride supercell structures with enhanced photodegradation activity

Abstract

New graphitic carbon nitride (g-C3N4) supercell structures, including microsheets, nanorods and microprisms were prepared via the two-step method of the calcination and hydrothermal post-treatment, in which the concentrations of bulk g-C3N4 precursors were controlled before the hydrothermal treatment. After hydrothermal treatment of 20, 100, 200 mg mL−1 bulk g-C3N4 precursor, the hexagonal unit cell parameters of as-prepared g-C3N4 supercell structures are: a = b = 16.46 Å, c = 6.49 Å, α = β = 90°, γ = 120°. The crystallographic structures, morphologies, optical and chemical properties of g-C3N4 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), electron diffraction (ED), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption/desorption isotherms, photoluminescence (PL) spectroscopy, and UV–vis diffuse reflectance spectroscopy (DRS). Photocatalytic performances of the g-C3N4 samples were evaluated by the degradation of Rhodamine B in an aqueous medium under visible-light irradiation. Photodegradation activity of as-prepared sheet-like g-C3N4 supercell structure, is approximately 1.5 times higher than that of bulk g-C3N4.