Effects of heat treatment on the structure and photocatalytic activity of polymer carbon nitride.

Heat treatment technology is usually used for the processing of metal materials. In this paper, polymer carbon nitride (g-C₃N₄) is secondarily calcined at 590 °C. A series of nitrogen-doped g-C₃N₄ are obtained by adjusting the holding time. The doping of nitrogen atoms changes the electronic structure of the catalyst and narrows the band gap. In addition, the escape of ammonia during the secondary calcinations leads to the increase in the specific surface area of the catalyst, which is helpful to enhance the photosensitization effect. Among them, the sample obtained by holding time at 2 h has the highest photogenerated carrier separation efficiency, the largest specific surface area and the best photocatalytic degradation of methylene blue. [ABSTRACT FROM AUTHOR]