Solar-light induced photocatalytic-persulfate activity of BiOCl0.5I0.5/NH2-MIL-88B(Fe) for tetracycline hydrochloride degradation

Photocatalysis coupling with persulfate advanced oxidation is a promising route to eliminate antibiotics from wastewater. BiOCl0.5I0.5 combined with NH2-MIL-88B(Fe) (BCI/NM-88B) heterojunction was constructed for enhancing the photocatalytic-persulfate activity toward tetracycline hydrochloride (TCH). The junction between BiOCl0.5I0.5 and NH2-MIL-88B(Fe) favored the separation and transfer of photo-induced e−/h+ pairs, boosting the visible-light utilization. Compared with BiOCl0.5I0.5 and NH2-MIL-88B(Fe), BCI/NM-88B exhibited the better removal efficiency of TCH. The optimal 3-BCI/NM-88B could remove 91.15 % TCH solution of 120 mg L−1 within 120 min, and declined to 85.86 % after five cycles. The photo-corrosion and the residue coverage leaded to the deactivation of 3-BCI/NM-88B. SO4− and OH radicals were the vital radicals in 3-BCI/NM-88B-assisted photocatalytic-persulfate system. [Display omitted] •BiOCl0.5I0.5 combined with NH2-MIL-88B(Fe) (BCI/NM-88B) heterojunction was constructed.•BCI/NM-88B enhanced the photocatalytic-persulfate activity toward TCH.•Optimal 3-BCI/NM-88B removed 91.15 % TCH solution of 120 mg L−1 within 120 min.•SO4− and OH radicals were the vital radicals of photocatalytic-persulfate system.