Synthesis g-C3N4 of high specific surface area by precursor pretreatment strategy with SBA-15 as a template and their photocatalytic activity toward degradation of rhodamine B

Abstract

Using SBA-15 as a template, high surface area porous graphitic carbon nitrides (g-C3N4) were successfully synthesized by pretreating melamine using hydrochloric acid, and fully characterized by Fourier-Transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron micrographs (SEM), N2 adsorption-desorption, ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence (PL) spectrum. The results of these analyses indicated that the g-C3N4 synthesized from HCl-pretreated melamine with SBA-15 as a template has enhanced specific surface area and increased the separation rate of the photogenerated electrons and holes compared with bulk g-C3N4, but didn’t change the structure of bulk g-C3N4. The photocatalytic activity of samples was evaluated by the degradation of rhodamine B (RhB) under xenon lamp. The results indicated that the activity was improved significantly with the increase of specific surface area. The rate constant for CN-3（HCl pretreatment melamine precursor and SBA-15 as a template） was 13 times as high as g-C3N4. Furthermore, the CN-3 catalyst exhibited outstanding structural and catalytic stability.