Construction of Z-scheme N-doped BiFeO3/NH2-MIL-53(Fe) with the synergy of hydrogen peroxide and visible-light-driven photo-Fenton degradation of organic contaminants

In this work, an efficient Z-scheme heterojunction consisting of perovskite and iron-based metal-organic framework (N-BiFeO3/NH2-MIL-53(Fe)) composite was fabricated by in-situ growth. The catalyst accelerates the separation of photogenerated carriers and broadens the absorption range of visible light, and acts as a heterogeneous Fenton-like catalyst for the degradation of tetracycline hydrochloride (TC-H). The structure, composition, morphology and optical properties of the catalyst were comprehensively investigated. Photocatalytic experiments showed that the composite exhibited higher degradation efficiency (88%) compared with pure N-BiFeO3 (40%) and pure Fe-MOF (71%). In addition, 99% of TC-H, 76% of ciprofloxacin, and 91% of sulfamethoxazole were degraded within 60 min under the visible light/N-BiFeO3/NH2-MIL-53(Fe)/H2O2 system. The effects of catalyst dosage, coexisting ions and other factors on the degradation performance were investigated, and good stability was shown. The experiment of free radical scavenger proved that the production of hydroxyl radicals was the main active substance for the degradation of TC-H, which accelerated the Fe(II)/Fe(III) cycle and promoted the efficient degradation of TC-H, the possible mechanism of the degradation of TC-H by visible light/ N-BiFeO3/NH2-MIL-53(Fe) /H2O2 system was discussed. Therefore, N-BiFeO3/NH2-MIL-53(Fe) can be used as an effective photocatalyst for the degradation of organic pollutants.