Effective photocatalytic degradation of sulfamethoxazole using tunable CaCu3Ti4O7 perovskite

En Lien; Rama Shanker Sahu; Wen-Ling Chen; Yang-Hsin Shih

doi:10.1016/j.chemosphere.2022.133744

Effective photocatalytic degradation of sulfamethoxazole using tunable CaCu₃Ti₄O₇ perovskite

Chemosphere. 2022 May:294:133744. doi: 10.1016/j.chemosphere.2022.133744. Epub 2022 Jan 28.

Authors

En Lien¹, Rama Shanker Sahu¹, Wen-Ling Chen², Yang-Hsin Shih³

Affiliations

¹ Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, ROC.
² Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, ROC; Institute of Food Safety and Health, National Taiwan University, No. 17, Xuzhou Rd., Taipei, 100, Taiwan, ROC; Department of Public Health, National Taiwan University, No. 17, Xuzhou Rd., Taipei, 100, Taiwan, ROC.
³ Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, ROC. Electronic address: yhs@ntu.edu.tw.

PMID: 35093422
DOI: 10.1016/j.chemosphere.2022.133744

Abstract

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 (∼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.

Keywords: CCTO Perovskite; Electrolytes; Photodegradation; Reactive halogen species; Sulfamethoxazole.

MeSH terms

Calcium Compounds
Oxides
Sulfamethoxazole* / chemistry
Titanium
Water Pollutants, Chemical* / chemistry

Substances

Calcium Compounds
Oxides
Water Pollutants, Chemical
perovskite
Titanium
Sulfamethoxazole