Accelerated Heterogeneous Fenton Reaction for Tetracycline Hydrochloride Degradation by Cu(I)-doped Fe3O4/GO Nanocomposites

Cu(I) doped Fe 3 O 4 nanoparticles was loaded onto graphene oxide, Cu-Fe 3 O 4 /GO with binary active sites and accelerated Fe(III)/Fe(II) cycle showed higher tetracycline hydrochloride oxidation efficiency than Fe 3 O 4 and Cu-Fe 3 O 4 , the influences of initial H 2 O 2 concentration, reaction pH, catalyst dosage, reaction temperature and radical scavengers on catalytic performance of Cu-Fe 3 O 4 /GO were investigated. The heterogeneous Fenton reaction over Cu-Fe 3 O 4 /GO surface contained Fe(III)/Fe(II) and Cu(II)/Cu(I) active sites, Fe species were the dominant active centers. Cu-Fe 3 O 4 nanoparticles and GO combined via C–O–Fe bond and formed a stable Cu-Fe 3 O 4 /GO conductive structure, which promoted electrons transfer between Cu-Fe 3 O 4 and H 2 O 2 , thus accelerating Fe(III)/Fe(II) and Cu(II)/Cu(I) cycles. GO significantly improved specific surface area, Cu-Fe 3 O 4 nanoparticles dispersibility, and adsorption performance of catalyst. Furthermore, the strong interaction between GO and Cu-Fe 3 O 4 prevented ions from leach, GO captured the soluble Fe(III) which was efficiently reduced to Fe(II) surf by surrounding H 2 O 2 and Cu(I) surf . The degradation efficiency maintained 80.7% after six cycles, the excellent stability can be ascribed to the strong interaction between Cu-Fe 3 O 4 and GO. Reactive oxygen species scavenging results indicated that surface-bound • OH surf played a dominating role, followed by aqueous • OH aq and superoxide radicals (O 2 •− ).