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 °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.