Chinese Journal of Catalysis ›› 2017, Vol. 38 ›› Issue (8): 1360-1372.

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Peroxymonosulfate activation by Mn3O4/metal-organic framework for degradation of refractory aqueous organic pollutant rhodamine B

Longxing Hua, Guihua Denga, Wencong Lub, Yongsheng Lua, Yuyao Zhanga   

  1. a School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China;
    b College of Sciences, Shanghai University, Shanghai 200444, China
  • Received:2017-04-26 Revised:2017-06-19 Online:2017-08-18 Published:2017-08-04
  • Supported by:

    This work was supported by the National Key Research and Development Program of China (2016YFB0700504).

Abstract:

An environmentally friendly Mn-oxide-supported metal-organic framework (MOF), Mn3O4/ZIF-8, was successfully prepared using a facile solvothermal method, with a formation mechanism proposed. The composite was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron microscopy, and Fourier-transform infrared spectroscopy. After characterization, the MOF was used to activate peroxymonosulfate (PMS) for degradation of the refractory pollutant rhodamine B (RhB) in water. The composite prepared at a 0.5:1 mass ratio of Mn3O4 to ZIF-8 possessed the highest catalytic activity with negligible Mn leaching. The maximum RhB degradation of approximately 98% was achieved at 0.4 g/L 0.5-Mn/ZIF-120, 0.3 g/L PMS, and 10 mg/L initial RhB concentration at a reaction temperature of 23℃. The RhB degradation followed first-order kinetics and was accelerated with increased 0.5-Mn/ZIF-120 and PMS dosages, decreased initial RhB concentration, and increased reaction temperature. Moreover, quenching tests indicated that ·OH was the predominant radical involved in the RhB degradation; the ·OH mainly originated from SO4-·and, hence, PMS. Mn3O4/ZIF-8 also displayed good reusability for RhB degradation in the presence of PMS over five runs, with a RhB degradation efficiency of more than 96% and Mn leaching of less than 5% for each run. Based on these findings, a RhB degradation mechanism was proposed.

Key words: Peroxymonosulfate activation, Refractory organic pollutant, Degradation, Metal-organic framework, Mn3O4/ZIF-8