The marriage of ferrocene and silicotungstate: An ingenious heterogeneous Fenton-like synergistic photocatalyst

The oxidation of 4-chlorophenol (4-CP) was firstly carried out by heterogeneous Fenton-like process in the presence of ferrocene-containing silicotungstate catalyst (denoted as FcSiW). The catalyst was successfully prepared by precipitation method in aqueous solution using ferrocene (Fc, or CpFeCp) and silicotungstic acid (SiW, or H4SiW12O40 center dot xH(2)O) as raw materials and the intrinsic relationship between structure and catalytic activity was fully studied. Under the suitable conditions, the prepared FcSiW exhibited high catalytic activity, especially under irradiation conditions. Moreover, the catalyst showed good reusability without significant performance drop after successive experimental runs and high stability with very low iron leaching. The strong interaction resulting from the close contact between Fc and polyoxometalate (POM) species contributes to the charge-transition from Fc to POM, which is in favor of its photocatalysis. A possible catalytic mechanism revealing the synergistic effect between the Fenton-like reaction of ferricinium and photocatalysis of SiW12O404- anions in FcSiW/H2O2 system was proposed on the basis of experiment results and previous reports. This novel highly active heterogeneous catalyst has the potential for wide range of application in wastewater pollutants treatment. (C) 2016 Elsevier B.V. All rights reserved.