Effect of heating time on structural, morphology, optical, and photocatalytic properties of g-C₃N₄ nanosheets*

Effect of heating time on the structural, morphology, optical, and photocatalytic properties of graphitic carbon nitride (g-C3N4) nanosheets prepared at 550 °C in Ar atmosphere is studied. The investigations are carried out by using x-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), UV–vis absorption, and photoluminescence (PL). At a heating temperature of 550 °C, g-C3N4 nanocrystals are formed after 0.5 h and become more orderly as the heating time increases. The surface area of the g-C3N4 nanosheets significantly increases as the preparation time increases. The g-C3N4 prepared in 2.5 h shows the highest photocatalytic performance, decomposing completely 10 ppm RhB solution under xenon lamp irradiation for 2.0 h.