Synthesis of graphitic carbon nitride from different precursors by fractional thermal polymerization method and their visible light induced photocatalytic activities

Graphitic carbon nitride(g-C3N4) polymer was successfully synthesized by a fractional thermal polymerization method using melamine, guanidine carbonate and dicyandiamide as precursors. The detailed characterization was carried out by TG-DTG, XRD, SEM, PL, DRS, XPS and BET. The photocatalytic performance was determined by degradation of methyl orange(MO) under visible light irradiation. g-C3N4 obtained from different raw materials and temperature showed different band gap, morphology and photocatalytic activities. The g-C3N4 could be obtained by the polymerization reaction of melamine, guanidine carbonate or dicyandiamide at 515, 550 or 515 °C, respectively. The treatment temperature affected the final properties of the g-C3N4 particles. The g-C3N4-M(melamine, 600 °C), g-C3N4-D(dicyandiamide, 590 °C) and g-C3N4-G (guanidine carbonate, 550 °C) particles showed the best MO degradation photocatalytic performances under visible light irradiation (>400 nm) for 120min.