Nitrogen self-doped high specific surface area graphite carbon nitride for photocatalytic degradating of methylene blue

Self-doped graphite carbon nitride (g-C3N4) is a hot topic in the field of photocatalysis. The g-C3N4 with nitrogen self-doped and higher specific surface area was obtained via adjusting the temperature of secondary calcination for 550 degrees C, 590 degrees C, and 625 degrees C, which will improve its photocatalytic properties. The sp(2) hybridized C is replaced by the nitrogen atom. It changes the electronic structure of the catalyst, allows the catalyst to display higher photo-generated carrier separation efficiency and a narrower bandgap than the original g-C3N4. In addition, the escape of ammonia gas in secondary calcinations results in a larger specific surface area, which will help the adsorption of dye and improvement photosensitive effects. Finally, the catalyst obtained at the secondary calcinations temperature of 590 degrees C had the best effect. It is an interesting phenomenon to obtain nitrogen self-doped carbon nitride after secondary calcinations, which provides a new idea for studying nitrogen doping of carbon nitride.