Photocatalytic degradation of tetracycline hydrochloride by novel Fe3O4/g-C3N4/rGO magnetic nanocomposites mechanism: modeling and optimization

Abstract

The photocatalytic degradation of antibiotics requires a good separation efficiency of photogenerated electron-hole pairs and a wide visible light absorption range. Current studies have discussed the successful preparation of ferroferric oxide/graphite carbon nitride/reduced graphene oxide (Fe3O4/g-C3N4/rGO). The phase structure and morphology of Fe3O4/g-C3N4/rGO composites were characterized by XRD, HR-TEM, SEM and EDS. The obtained composites were used to degrade tetracycline hydrochloride to evaluate its photocatalytic activity. The effects of four variables on the degradation of tetracycline hydrochloride were analyzed by the response surface method and artificial intelligence (gradient regression tree, random forest, artificial neural network, etc.). The results showed that the graphite carbon nitride in the catalyst maintained its original structure and that the photocatalytic activity was significantly improved. The degradation rate of tetracycline hydrochloride was 86.7%. The artificial neural network combined with a genetic algorithm was the best model for predicting the degradation of tetracycline hydrochloride by nanocomposites. The degradation of tetracycline hydrochloride was in accordance with the pseudosecond-order kinetic model. The proposed photocatalytic mechanism study indicated that ∙O2− and ∙OH radicals are the foremost reactive species that have vital roles in the photodegradation process. This finding provides a theoretical reference for the photocatalytic degradation of antibiotics (or analogous pollutants) in wastewater.

Recent advances in removal of pharmaceutical pollutants in wastewater using metal oxides and carbonaceous materials as photocatalysts: a review

“…Fe 3 O 4 /g-C 3 N 4 /rGO exhibited 86.7% degradation rate of tetracycline hydrochloride, following pseudo-secondorder kinetics. 613 The proposed mechanism suggested •O 2 − and •OH radicals as the most reactive species in the photocatalytic degradation of tetracycline. Ghoreishian et al 614 reported sonophotocatalytic degradation of tetracycline using a flower-like rGO/CdWO 4 composite under simulated visible-light irradiation.…”

“…Binary and ternary graphitic composite materials have been reported as photocatalysts in the removal of tetracycline from aqueous solution. [605][606][607][608][609][610][611][612][613][614][615][616][617][618][619][620][621] According to Ren et al, 605 a red mud/graphene oxide (mass RSC Applied Interfaces Review ratio: 93 : 7) composite attained the best degradation rate for tetracycline (79.8%) compared to raw red mud under visible light within 80 min owing to its enhanced specific surface area, light absorption and charge separation. Porous hydroxyapatite (Hap) hollow microspheres as a source of cheap and green photocatalysts have been harnessed in fabricating rGO/Hap composites.…”