Enhanced adsorption and degradation of methylene blue over mixed niobium-cerium oxide-Unraveling the synergy between Nb and Ce in advanced oxidation processes

JOURNAL OF HAZARDOUS MATERIALS

卷:415

Article

Wolski, Lukasz¹  Sobanska, Kamila²  Walkowiak, Adrian¹  Akhmetova, Kamila²  Grybos, Joanna²  Frankowski, Marcin¹  Ziolek, Maria¹  Pietrzyk, Piotr² 

[1] Adam Mickiewicz Univ, Fac Chem, Ul Uniwersytetu Poznanskiego 8, PL-61614 Poznan, Poland

[2] Jagiellonian Univ, Fac Chem, Ul Gronostajowa 2, PL-30387 Krakow, Poland

关键词: Mixed oxides;    Reactive oxygen species;    Fenton-like processes;    Wet peroxide oxidation;    Methylene blue degradation;   

DOI  :  10.1016/j.jhazmat.2021.125665

来源: Elsevier

【 摘 要 】

Formation of reactive oxygen species (ROS) via H2O2 activation is of vital importance in catalytic environmental chemistry, especially in degradation of organic pollutants. A new mixed niobium-cerium oxide (NbCeOx) was tailored for this purpose. A thorough structural and chemical characterization of NbCeOx along with CeO2 and Nb2O5 reference materials was carried out using TEM/STEM/EDS, SEM, XRD, XPS, EPR, UV-vis and N2 physisorption. The ability of the catalysts to activate H2O2 towards ROS formation was assessed on the basis of EPR and Raman measurements. Catalytic activity of the oxides was evaluated in degradation of methylene blue (MB) as a model pollutant. Very high activity of NbCeOx was attributed to the mixed redox-acidic nature of its surface, which originated from the synergy between Nb and Ce species. These two properties (redox activity and acidity) ensured convenient conditions for efficient activation of H2O2 and degradation of MB. The activity of NbCeOx in MB degradation was found 3 times higher than that of the commercial Nb2O5 CBMM catalyst and 240 times higher than that of CeO2. The mechanism of the degradation reaction was found to be an adsorption-triggered process initiated by hydroxyl radicals, generated on the surface via the transformation of O2-center dot/O22-.

【 授权许可】

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