Constructing g-C3N4-x/MoO3 Z-scheme heterojunction for photodegradation of tetracycline

Abstract

Utilizing photocatalysis to degrade antibiotics in wastewater is a vital strategy. Here, a Z-scheme heterojunction was synthesized, consisting of defect-rich porous g-C₃N₄ and MoO₃, which exhibits remarkable photocatalytic degradation of tetracycline (TC). The results revealed that the optimal heterojunction sample exhibited a 2.47-fold enhancement of degradation efficiency compared with porous g-C₃N_4-x. Characterization analysis shows that the significant enhancement is attributed to the synergistic effects arising from the Z-scheme heterostructure and the introduction of nitrogen (N) defects, which collectively enhance the charge separation and light absorption capabilities of the material. Electron paramagnetic resonance (EPR) spectroscopy and free radical quenching experiments indicate that the vital degradation mechanism is the assault of •O₂^– and •OH on tetracycline. Additionally, the LC-MS studies demonstrated possible intermediates and degradation pathway of TC. The toxicity simulation analysis revealed that the heterojunction sample effectively mitigated the toxicity of tetracycline solution. This catalyst exhibits promising potential for applications in the elimination of antibiotics from aquatic environments.