Direct Z-scheme MIL-100(Fe)/BiOBr heterojunctions:Construction and photo-Fenton degradation for sulfamethoxazole
A series of MIL-100(Fe)/BiOBr direct Z-scheme heterojunctions was fabricated by the in-situ precipita-tion method.The crystal structures,micromorphology,optical adsorption property,and chemical states were estimat-ed by powder X-ray diffraction(PXRD),Fourier transforms infrared(FTIR)spectra,UV-Vis diffuse reflectance spec-tra(UV-Vis DRS),scanning electron microscopy(SEM),high-resolution transmission electron microscope(HRTEM)and X-ray photoelectron spectra(XPS).The performance of photo-Fenton degradation for sulfamethoxazole(SMX)under low-powered light emitting diode lamp irradiation was explored.The catalytic degradation efficiency of SMX(5 mg·L-1)in the optimal reaction system(MB-7/Vis/H2O2,MB-7 was prepared when the mass of MIL-100(Fe)was 70％of the mass of BiOBr)could reach 99.8％upon 70 min illumination.Meanwhile,the effects of H2O2 concentra-tion,catalyst dosage,pH,and co-existing inorganic anions on SMX removal over MB-7/Vis/H2O2 were studied.The removal efficiency of SMX could reach above 95％after five consecutive operations,suggesting that MB-7 had good stability and reusability.The possible catalytic mechanism was unraveled by photoluminescence(PL)spectra,elec-trochemical measurements,radical trapping experiments,and electronic spin resonance(ESR)technique.The enhanced photo-Fenton reactivity could be attributed to the fabrication of heterostructures accelerated separation photocarriers and then induced the generation of reactive species and Fe3+/Fe2+redox cycle.
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维普
