One-step synthesis of highly reactive g-C3N4

Graphitic carbon nitride (g-C3N4) with well-controlled properties are the key for photocatalysis water splitting and organic pollutant degradation. A facile template-free synthesis method was utilized to optimize the polymerization temperature of melamine and urea for the preparation of highly active g-C3N4. The polymerization was carried out at different temperatures and ramping rate in tightly sealed crucible system with open air conditions. The crystalline and tri-s-triazine periodicity was significantly improved with increasing polymerization temperature. The results demonstrated that graphitic carbon nitride could not be fully formed below 550 degrees C. It was also found that the precursors and heating rate had a big influence on the photocatalytic activities. Higher photocatalytic activities were achieved by g-C3N4 synthesized from urea at a lower heating rate.