Facile Synthesis of Metal Doped Graphite Carbon Nitride for Photocatalytic Degradation of Tetracycline Under Visible Light Irradiation

Abstract

Using semiconductor photocatalysts for antibiotic contaminants degradation under visible light has become a hot topic in recent years. Herein, a novel cadmium doped graphite phase carbon nitride (Cd/g-C3N4) photocatalyst was successfully constructed via 60 °C oil bath method to degrade tetracycline. Experimental and characterization results revealed that cadmium was well doped at g-C3N4 surface and exhibited high intercontact with g-C3N4. Meanwhile, Cd/g-C3N4 presented excellent electrical conductivity and inhibited the recombination of electron-hole pairs. The introduction of cadmium significantly improved the photocatalytic activity and the degradation efficiency of 10 Cd/g-C3N4 reached to 89.09%, which was exceeded 2.0 times than pure g-C3N4 (43.99%). Additionally, the quenching experiments and electron spin-resonance tests exhibited holes (h+), hydroxyl radicals (•OH) and superoxide radicals (•O2−) were dominated active species in TC degradation. Furthermore, the effects of various conditions on the reaction process, such as different pH, initial TC concentrations and catalyst dosage, were also researched. This work gives a reasonable point to synthesize high-efficiency and economic photocatalysts.