Enhanced photoelectrochemical degradation of toxic tetracycline by Au nanoparticles modified Co doped Fe2O3 electrode under mild conditions

Abstract

• Novel Au modified Co doped Fe 2 O 3 photoelectrode was designed and synthesized. • Doping Co and surface Au reduced pairs recombination and promoted conductivity. • This photoelectrode showed good activity and reusability to tetracycline degradation. • Generated hydroxyl and superoxide radical played critical roles to the degradation. The accumulation of Tetracycline (TCH) in water damages the ecosystem and endanger human health. Although traditional Fenton reactions can degrade the antibiotics effectively, introduced strong oxidants and irrecoverable catalyst powders during the catalytic process bring new environmental problems. In this paper, novel Au nanoparticles modified Co doped Fe 2 O 3 (Au/Co:Fe 2 O 3 ) composited electrodes were prepared for the photoelectrochemical degradation of TCH under mild conditions. Due to the significantly reduced recombination of photogenerated electron-hole pairs and promoted electrical conductivity, Au/Co:Fe 2 O 3 electrode exhibited removal efficiency of 75 % for 180 min without any additional oxidants at low potential. Moreover, the Au/Co:Fe 2 O 3 also showed excellent reusability and long-term stability. Under light irradiation, generated O 2 − and OH species played critical roles in the degradation of TCH.