Template-free Preparation of Porous g-C3N4 for Visible-light Catalysis

A novel and facile template-free method was presented to fabricate a porous g-C3N4 (graphite-like carbon nitaide) by combining ultrasonic treatment with hydrothermal modification in the presence of sulfuric acid. Particle size analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and UV-vis diffuse reflectance spectra (DRS) were adopted to analyze its structure, morphology and properties. And the photocatalytic activities of the as-prepared samples were also evaluated by decomposing methyl orange (MO) and Rhodamine B (RhB) in aqueous solution under visible light illumination. The results show that combining ultrasonic treatment with hydrothermal modification is favorable to improve the porosity of g-C3N4, which can increase the ability to absorb pollutants and inhibit the recombination of photo-generated carriers, thereby enhancing the visible-light photocatalytic property.