A core-shell structure formed by A-site defects in LaFeO3/two-dimensional BiOCl nanosheets for highly efficient photocatalytic degradation of ciprofloxacin: Insights into performance and mechanism

A Using A-site defective LaFeO₃ as the core and two-dimensional BiOCl nanosheets as the shell, a core-shell structure with a Z-type heterojunction was constructed. The photocatalytic activity of 0.7B-X (where X represents the mass fraction of defective LaFeO₃ = 50, 100, 150) was investigated. Experimental studies indicate that the heterojunction structure suppresses the recombination rate of photo-generated carriers and enhances the photocatalyst's ability to absorb visible light. Among these, 0.7B-100 achieved a CIP degradation rate of 88.9 % within 60 min under no activator conditions, which is 1.7 times and 2.4 times higher than that of 0.7LFO and BiOCl, respectively. The degradation rate remained at 79.8 % after 6 cycles, and the concentration of iron ion leaching rate was very low, and the TOC mineralization rate remained at 68.0 %. Meanwhile, 0.7B-100 has a very impressive resistance to acid and alkali, with a degradation rate of 77.1 % under strong alkali conditions, k = 0.01979 min −1 , and 80 % under weak alkali conditions. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to study the composition of the physical phases, and scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to study the microstructure, UV-diffuse reflectance and UV-diffuse reflectance. Structure, UV–vis DRS and electrochemical tests to study its photoelectric properties, and fully automated physical adsorption tester (BET) to investigate its specific surface area and pore size. The reusable and stable photocatalysts provide a new idea for photocatalytic degradation of antibiotics in water with high efficiency.