Direct microwave heating synthesis and characterization of highly efficient g-C3N4 photocatalyst

Abstract

Graphitic carbon nitride (g-C3N4) material was rapidly synthesized by direct microwave heating method with different microwave powers and irradiation reaction periods of time. Phase, functional group, surface morphology and optical properties of as-prepared g-C3N4 samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflectance spectroscopy and photoluminescence (PL) spectroscopy. The samples synthesized by direct microwave heating at 600–800 W for 9–15 min were g-C3N4 single phase with typical CN stretching vibration and out-of-plane bending vibration of C–N heterocycle and good absorption in the visible light region. The photocatalytic activity of g-C3N4 was evaluated through the degradation of methylene blue (MB), methyl orange (MO) and rhodamine B (RhB) under visible light irradiation. In this research, the g-C3N4 sample synthesized at 800 W microwave power for 15 min has the best photocatalytic performance in degrading of 91.82 % MB, 81.86% MO and 97.48% RhB within 60 min.