Ultrafine silver nanoparticles deposited on sodium-doped graphitic carbon nitride towards enhanced photocatalytic degradation of dyes and antibiotics under visible light irradiation

Ultrafine nanoparticle or single-atom deposition can improve the photocatalytic activity of graphitic carbon nitride (g-C₃N₄) efficiently. Herein, we prepared sodium ion-doped g-C₃N₄ photocatalyst deposited with ultrafine silver nanoparticles (<1 nm) by a facile and efficient one-pot route. Sodium sulfate was used as an inexpensive and green precursor to achieve the doping of sodium ions to g-C₃N₄. Ultrafine silver nanoparticles were anchored in-situ on the surface of g-C₃N₄ to construct Schottky heterojunction during thermal polycondensation. The band gap and valence band position of g-C₃N₄ were tuned by sodium ion doping, which enhanced visible light absorption and oxidizing ability. Both ultrafine silver nanoparticles and sodium ions accelerated the migration of photogenerated electrons and promoted the separation of photogenerated carries. These merits were synergistic to cause the excellent enhanced photocatalytic activity of sodium ion-doped g-C₃N₄ deposited with ultrafine silver nanoparticles in degradation of Rhodamine B and tetracycline hydrochloride under visible light irradiation.