Enhanced visible light photocatalytic degradation of tetracycline by MoS_2/ Ag/g-C_3N_4 Z-scheme composites with peroxymonosulfate

摘要

In current study, the combined strategy of Ag deposition and MoS2 coupling was taken to co-modify g-C3N4 nanosheets to construct MoS2/Ag/g-C3N4 (MS/A/CN) Z-scheme composite. The as-prepared MS/A/CN composite was used to photocatalytic degrade TC with PMS presence under visible light irradiation. The MS/A/CN/Vis/PMS system displayed excellent and rapid degradation of tetracycline (TC) due to the synergistic effect of photocatalysis and PMS activation, approximately 98.9% of TC being removal in 50 min. The effects of the contents of Ag deposition and MoS2 coupling and operation parameters including catalysts dosage, PMS concentration, initial pH and natural water on TC degradation efficiency were investigated. Quenching tests and electron paramagnetic resonance measurements (EPR) confirmed that (OH)-O-center dot, O-center dot(2)- and SO4 center dot- are the primary reactive oxygen species MS/A/CN/Vis/PMS system. Meanwhile, the degraded products of TC was determined via gas chromatography-mass spectrometer (GC-MS) testing and the mechanism of enhanced TC degradation in MS/A/CN/Vis/PMS system was proposed. This work will give insight on rapidly and efficiently removing the organic pollutant in water environment.