A novel flower-like Z-type heterojunction CuS/Bi7O9I3 composite catalyst prepared under mild conditions for degradation of antibiotics and sterilization under visible light

Abstract

In order to solve problems of the photo-generated charge recombination and low utilization efficiency of visible light in achieving green and sustainable development, a novel flower-like Z-type heterojunction CuS/Bi₇O₉I₃ composite catalyst was successfully prepared through a facile and mild process. The preparatory conditions of Bi₇O₉I₃ and CuS are low temperature and normal pressure with environment friendly reagents. The degradation performance of the catalyst was evaluated using ciprofloxacin (CIP) antibiotic. The results showed that degradation rate of the CuS/Bi₇O₉I₃ composite catalyst was 5 and 4 times that of the single CuS and Bi₇O₉I₃ catalysts, respectively. The actual performance of the catalyst was evaluated using simulated wastewater containing different ions and real water sources. Results showed that the new CuS/Bi₇O₉I₃ composite catalyst has excellent degradation and practical performances. At the same time, there is a synergistic effect between the photothermal and catalytic effects of the catalyst. The rapid temperature increase obviously inhibited the biological activity of bacteria, thereby affecting its metabolism and enhancing the destruction of the composite catalyst. Finally, using the free radical capture, VB-XPS and ESR measurements, photocatalytic mechanisms are proposed.