Effective photocatalytic degradation of sulfamethoxazole using tunable CaCu3Ti4O7 perovskite

Sulfamethoxazole (SMX) is largely prescribed for bacterial infections but raises a major concern over generation of antibiotic-resistant bacteria in the environment. This study employed various perovskite-type photocatalysts, made by two-step synthesis procedures, to remove SMX. The as-synthesized CaCu3Ti4O7 (CCTO) perovskites were characterized by XRD, SEM-EDX, and DLS. Complete degradation (similar to 99%; k(obs) = 0.0279 min(-1)) of SMX was recorded under UV-light irradiation for 90 min in the presence of CCTO. SMX removal rate was investigated under various reaction conditions including pH, catalyst dose, electrolyte (NaCl and NaBr). The astonishing rate of SMX removal (k(obs) = 0.0614 min(-1)) was observed with the addition of 50 mM NaBr electrolytes in the reaction, which might imply that the appearance of halogen reactive species. CCTO-MS particles were aggregated in traces when the electrolytes concentration increases, resulting in reduced rate of SMX. The SMX concentration abatement and the formation of possible intermediates during photocatalytic reaction were analyzed. The upshot of this study reveals that the inexpensive and environmentally benign CCTO perovskite photocatalyst could be applied for the treatments of emerging contaminants in the future.

Automated summary

Sulfamethoxazole (SMX), a widely used antibiotic, has raised concerns over the development of antibiotic-resistant bacteria in the environment. This study investigated the use of perovskite-type photocatalysts for the removal of SMX. The CaCu3Ti4O7 (CCTO) perovskites showed excellent degradation efficiency under UV-light irradiation, with the addition of NaBr electrolytes further enhancing the removal rate. The study suggests that the inexpensive and environmentally benign CCTO perovskite photocatalyst can be applied for the treatment of emerging contaminants in the future.