RESUMO
Ru-doped Co9S8 hollow porous polyhedrons (Ru-Co9S8 HPPs) derived from zeolitic-imidazolate-frameworks were synthesized through hydrothermal coprecipitation and thermal decomposition methods. The results indicate that Ru-Co9S8-500 HPPs possess a strong Ru-Co synergistic effect, large electrochemical surface area, and sufficient active sites, endowing them with excellent hydrogen evolution reaction performance.
RESUMO
In this study, porous magnetic CoFe2O4 nanocrystals (NCs) were successfully synthesized by using bimetal-organic framework (MOF) as a precursor, and used as catalysts to activate peroxymonosulfate (PMS) for the removal of chloramphenicol (CAP) in the solution. The structure and physicochemical properties of CoFe2O4 NCs were thoroughly examined by a series of characterization techniques. The results revealed as-synthesized CoFe2O4 had a nanorod-shaped structure with high specific surface area (83.00 m2 g-1) and pore volume (0.31 cm3 g-1). Furthermore, the degradation efficiency (100%) and the removal of total organic carbon (68.09%) were achieved after 120 min with 0.1 g/L CoFe2O4 NCs, 2 mM PMS and 10 mg/L CAP at pH of 8.20. In addition, effects of catalyst dosage, PMS dosage, initial pH values, CAP concentration and co-existing anions as well as natural organic matters in the solution on the degradation efficiencies were studied and all the removal can be well fitted with pseudo-first-order kinetic model (R2 > 0.96). Sulfate radicals (SO4â¢-) and hydroxyl radicals (HOâ¢) were proved to be two main reactive species for CAP removal in CoFe2O4/PMS system based on quenching experiments. CAP was degraded by the main pathways of dichlorination, denitration, decarboxylation, hydroxylation, ring cleavage and chain cleavage on CoFe2O4/PMS system through high performance liquid chromatograph-mass spectrometry analysis. We believe that this study would be very meaningful to promote the applications of MOFs-derived catalysts on the SO4â¢- based advanced oxidation processes (SR-AOPs) for the environmental remediation.