Photocatalytic degradation of tetracycline by Phosphorus-doped carbon nitride tube combined with peroxydisulfate under visible light irradiation

Abstract

Photocatalysis has been regarded as a kind of environmentally friendly advanced oxidation process to eliminate pollutants. In this work, Phosphorus-doped carbon nitride tube (PCN) was synthesized via a hydrothermal calcination method and applied to degrade tetracycline (TC) through combing with peroxydisulfate (PDS) under visible light irradiation. Experimental results showed that the optimized catalysts PCN-5 exhibited superior degradation performance and reusability for TC degradation. 96.4% TC could be degraded for optimal PCN-5 with 0.3 g·L−1 catalysts and 1.0 g·L−1 PDS under visible light within 60 min. In addition, the degradation rate constant for TC of PCN + PDS + Vis system was still above 85% after five uses. Radical trapping experiment indicating that O2·− is the dominant radical for TC degradation. The findings of this work revealed the potential application of the PCN + PDS + Vis system toward degrading contaminants in wastewater. HIGHLIGHTS Phosphorus-doped carbon nitride tube was successfully synthesized.; PCN-5 + PDS + Vis system exhibited excellent TC degradation performance and reusability.; O2·− is the dominant radical for TC degradation.;

Keywords

• carbon nitride tube
• peroxydisulfate
• photocatalytic
• tetracycline