One-pot thermal polymerization route to prepare N-deficient modified g-C3N4 for the degradation of tetracycline by the synergistic effect of photocatalysis and persulfate-based advanced oxidation process

N-deficient g-C3N4 (CNx) photocatalyst was synthesized via a simple one-step thermal polymerization of urea and oxamide for the degradation of tetracycline (TC) under visible-light irradiation in the presence of persulfate (PS) activation. The microstructure and morphology of CNx were investigated by a host of characteristic technologies. The experimental result revealed that CNx/PS system displays a high efficiency in the photocatalytic process of TC degradation. The effects of different environmental factors (catalyst dose, PS dose, initial TC concentration and initial pH) on the degradation of the system were investigated. The possible intermediates products were discussed based on the liquid chromatography-mass spectrometry (LC-MS) analysis. Moreover, the toxicity of the TC solution over CNx/PS synergistic photocatalytic system was studied by the culture of bean sprouts, demonstrated that the aquatic toxicity of the TC after degradation of the system was effectively reduced.

Automated summary

A nitrogen-deficient g-C3N4 (CNx) photocatalyst was synthesized through thermal polymerization of urea and oxamide for tetracycline degradation under visible light with persulfate activation. The CNx/PS system showed high efficiency in degrading TC, with factors like catalyst and PS dosage, initial TC concentration, and pH affecting the degradation process. LC-MS analysis was used to identify intermediate products, and toxicity of the TC solution was effectively reduced after degradation.