LaFeO3/MgFe2O4 hybrids for boosting the solar-light photocatalytic persulfate oxidation of tetracycline hydrochloride.

LaFeO 3 /MgFe 2 O 4 heterojunctions were prepared via the sol-gel route to enhance solar-light induced photo-persulfate degradation of tetracycline hydrochloride (TCH). LaFeO 3 /MgFe 2 O 4 exhibited the better removal efficiency of TCH in comparison to LaFeO 3 and MgFe 2 O 4. The photo-persulfate activity of LaFeO 3 /MgFe 2 O 4 was intensively affected by LaFeO 3 content, pH, and inorganic salts. Under the optimal conditions, 2-LaFeO 3 /MgFe 2 O 4 with a nominal LaFeO 3 content of 10 wt % presented the removal efficiency of 97.01 %, while declined to 85.40 % after ninth-cycle test. The lattice defects formed in LaFeO 3 and MgFe 2 O 4 acted as the active sites for TCH adsorption and photon capture. The oxygen-defected tight interface between LaFeO 3 and MgFe 2 O 4 was favorable for the separation and migration of photo-induce e-/h+ pairs, boosting solar-light response for photo-persulfate activity of LaFeO 3 /MgFe 2 O 4. However, the long-term photo-corrosion inevitably induced to the change in valance states of surface compositions, weakening the photo-persulfate performance in TCH elimination. [Display omitted] • LaFeO 3 /MgFe 2 O 4 hybrids were prepared via the sol-gel approach. • LaFeO 3 /MgFe 2 O 4 had the strong solar-light photo-persulfate activity for TCH degradation. • The tight interface favored the transfer and migration of photo-induced e-/h+ pairs. • Photo-induced radicals and Fe2+/Fe3+ couples promoted the persulfate oxidation. [ABSTRACT FROM AUTHOR]