Cobalt doped bismuth oxysulfide with abundant oxygen vacancies towards tetracycline degradation through peroxymonosulfate activation

Herein, Co doped Bi2O2S catalysts (denoted as CBOS) with different Co doping contents were successfully fabricated through a facile hydrothermal reaction and Co species could be uniformly distributed in the crystal structure of Bi2O2S. The catalytic performance of CBOS catalyst for the degradation of tetracycline (TC) is ca. 2.1-fold higher than that of pristine Bi2O2S by peroxymonosulfate (PMS) activation and its catalytic activity could be enhanced with the increase of catalyst loading, PMS concentration, reaction temperature and the decrease of TC concentration, while the CBOS catalyst also showed high catalytic activity at the pH range of 3–9 and for other contaminants in aqueous solution. The suitable content of Co doping, the rich oxygen vacancies and the redox property of Co species on CBOS surface could be attributed to its highly enhanced performance via the experimental analysis and DFT calculations. Radical scavenging and ESR experiments confirmed the formation of reactive radical species (SO4–, O2−and 1O2) and the possible catalytic degradation pathways for TC were given according to the LC-MS analysis of degradation intermediates in CBOS/PMS system finally. The present work provides a promising perspective for the preparation of Co-based catalysts aiming at the treatment of contaminated water through the PMS activation.