Fabrication of Na, Cl co-doped graphitic carbon nitride with enhanced photocatalytic activity for degradation of dyes and antibiotics

Co-doping is a promising approach to change the electronic structure and increase the photocatalytic ability of graphitic carbon nitride (g-C₃N₄). Here, we reported a facile and green fabrication of Na, Cl co-doped g-C₃N₄ photocatalysts. In the fabrication, sodium and chlorine were incorporated into g-C₃N₄ synchronously. The bandgap of Na, Cl co-doped g-C₃N₄ decreased compared with pure g-C₃N₄ and the position of the valence band moved in the direction of enhanced oxidizing power. The co-doped photocatalysts exhibited the improved visible-light absorption and the reduced recombination rate of photogenerated electrons and holes. As a result, photocatalytic activity of Na, Cl co-doped g-C₃N₄ was remarkably improved for the photodegradation of rhodamine B and tetracycline hydrochloride under visible light irradiation. The photocatalysis mechanism of Na, Cl co-doped g-C₃N₄ was also discussed according to the results of active species trapping experiments.