Attached meso-tetra (4-carboxyphenyl) porphyrin copper (II) to BiOCl for enhanced photocatalytic performance in antibiotics degradation

Abstract

Bismuth oxychloride (BiOCl) has been considerably accepted as a photocatalyst due to its excellent photoelectrochemical properties, low cost and corrosion resistance. However, its further application has not progressed due to limited visible-light utilization and quick recombination of photoexcited carriers. In this work, a series of meso-tetra (4-carboxyphenyl) porphyrin copper (II) (CuTCPP) hybridized BiOCl composites (CuTCPP/BiOCl) were synthesized to use as an efficient visible-light responsive photocatalyst for the degradation of antibiotics pollutants in the wastewater systems. The characterization results confirmed that the 2D fusiform-shaped CuTCPP nanosheets were successfully inserted into hierarchical flower-like BiOCl. The photocatalytic degradation of several typical antibiotics (tetracycline, enrofloxacin and ciprofloxacin) demonstrated that CuTCPP/BiOCl showed better photocatalytic activities than pure BiOCl. Further, 0.5 wt% CuTCPP/BiOCl manifested the optimal photocatalytic efficiency for decomposing the antibiotics, and its degradation rate constant was about 2.84 times higher than that of pristine BiOCl. The significantly improved photocatalytic performance was mainly due to the promotion of visible light harvesting and enhanced separation of photogenerated carriers after the introduction of the macrocyclic CuTCPP. The radical substances determination confirmed that active •O2−, h+ and •OH existed in the photocatalytic removal of antibiotic, in which •O2− was the main reactive oxidizing species. The excellent degradation efficiency of CuTCPP/BiOCl reveals its great potential as photocatalysts for use in the alleviation of antibiotic contaminants and wastewater purification.