Facile synthesis of nitrogen deficient graphitic carbon nitride for photocatalytic hydrogen production activity

A nitrogen-deficient g-C3N4 photocatalyst was prepared by a combination of ultrasound and thermal condensation methods. The nitrogen deficiency was confirmed by XPS measurements through the high peak area ratio between C-C and N-C--N bonds. The obtained photocatalyst showed a H2 production rate of 3.90 mmolg-1h- 1 (sunlight) and 4.1 mmolg-1h- 1 (Xenon light), which is about -10 and -11 times higher than bare g-C3N4, respectively. The superior activity obtained was attributed to the extended visible light absorption and improved charge carrier separation due to the presence of nitrogen defects in g-C3N4.