Highly efficient photocatalytic degradation for antibiotics and mechanism insight for Bi2S3/g-C3N4 with fast interfacial charges transfer and excellent stability

Bi2S3/g-C3N4 (BSCN) samples with different mass ratios of CN to BS were prepared by a facile and practicable hydrothermal method with 2D g-C3N4 nanosheets (CN). The microscopic morphology and structure of pure CN, BS and BSCN were measured by multiple testing methods. Analysis results show that the BSCN was prepared successfully, and the Bi2S3 nanoparticles closely and uniformly adhered to the surface of CN with sheet-like structure. The introduction of Bi2S3 did not change the structure of the CN. The results of the ultraviolet-visible spectroscopic analysis, photoluminescence spectra and electrochemical performance indicated that BSCN showed superior visible-light response compared with CN, and the separation and transfer efficiency of photogener-ated carriers was significantly improved. With the decrease of mass ratio of CN/BS, the photocatalytic activity of BSCN initially increased and then decreased for 20 ppm of Rhodamine B solution (RhB), and the Bi2S3/g-C3N4-B with a mass ratio of 8:1 for CN to BS showed optimal photocatalytic performance (98.98%). Furthermore, the Bi2S3/g-C3N4-B exhibited apparent degradation effects (1.021 x 10(-2), 0.879 x 10(-2) and 0.793 x10(-2) min(-1)) to three kinds of antibiotics (tetracycline, ciprofloxacin, and oxytetracycline). The BSCN samples still maintained higher degradation efficiency after five cycles of degradation to tetracycline. The capture experiments and the electron spin resonance (ESR) spectra analysis indicated that the h(+) and center dot O-2(-) played a major role, and center dot OH played secondary role during the photocatalytic reaction. (C) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

BSCN samples with different mass ratios of CN to BS were successfully prepared using a hydrothermal method, allowing Bi2S3 nanoparticles to adhere closely to the surface of CN nanosheets while maintaining the structure of CN. BSCN demonstrated enhanced visible-light response and improved separation and transfer efficiency of photogenerated carriers, resulting in superior photocatalytic activity and degradation effects on dyes and antibiotics.