Preparation of meso-tetraphenyl porphyrin modified defect-rich BiOCl with enhanced visible-light photocatalytic activity for antibiotic degradation and mechanism insight

• Main Authors: Pei Zhao, Yan Huang, Jiawu Chen, Shouyan Shao, Haochi Miao, Jiexiang Xia, Chunman Jia, Mingqing Hua
• Format: Article
• Language: English
• Published: Elsevier 2020-09-01
• Series: Journal of Photochemistry and Photobiology
• Subjects: Defect-rich BiOCl; Porphyrin; Photocatalytic; Antibiotics; Mechanism
• Online Access: http://www.sciencedirect.com/science/article/pii/S2666469020300142

The exploration of effective photocatalysts used in wastewater treatment containing antibiotics is of significant importance for addressing the universal environment problems. In this work, the meso-tetraphenyl porphyrin (TPP) with conjugated macrocyclic π-electrons structure was successfully combined with defect-rich BiOCl to form ultrathin sheet-like TPP/defect-rich BiOCl composite as visible-light-responsive photocatalyst. The morphologies, crystal structures, chemical constitutions, optical and photo-electrochemical properties of the as-obtained photocatalyst were determined. The TPP/defect-rich BiOCl composite showed enhanced photocatalytic ability for the degradation of colorless antibiotic TC, CIP and ENR under visible light irradiation compared to defect-rich BiOCl. The effect of different TPP contents on the photodegradation activity was also investigated, and 2 wt% TPP/defect-rich BiOCl exhibited the optimal photocatalytic ability. According to the radicals trapping experiments and electron spin resonance (ESR), the hole (h+), superoxide radical (O2•−) and hydroxyl radical (•OH) contributed to the process of organic pollutant photo-degradation. The good recyclability of the photocatalyst was verified through cyclic measurements. Furthermore, a possible photodegradation mechanism was raised to clarify the effective separation and migration process of photo-induced charge carriers.