Surface decorated coral-like magnetic BiFeO3 with Au nanoparticles for effective sunlight photodegradation of 2,4-D and E. coli inactivation

Abstract

In this report, gold nanoparticle-decorated on the coral-like magnetic BiFeO3 (Au-BiFeO3) composite has been successfully fabricated by facile two-steps hydrothermal technique. Incorporation of Au nanoparticles on the BiFeO3 enabled effective harvesting sunlight for 2,4-dichlorophenoxyacetic acid (2,4-D) photodegradation and Escherichia coli (E. coli) inactivation on the heterojunction structures. The Au-BiFeO3 composite exhibited ameliorated photoactivities toward pollutant photodegradation and bacterial disinfection as compared to that of bare BiFeO3. The findings of these studies implied that decorating of Au on the coral-like BiFeO3 can greatly delay the recombination process of the charge carriers produced by photon absorption and thus enhanced the photoactivity of the BiFeO3. The possible photocatalytic mechanism was also postulated and supported by photoluminescence and electronic investigations. The radical trapping and electron spin resonance outcomes supported the role of the oxidative active species and its interaction for the degradation of 2,4-D. The intermediates responsible for the photodegradation have also been detected. Additionally, the prepared composite can be easily recovered through an external magnet and demonstrated good reusability within minimal release of deposited Au after six runs.