Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5747203 | Chemosphere | 2017 | 10 Pages |
â¢I-GAC was fabricated and utilized in heterogeneous IO4â oxidation process.â¢I-GAC exhibited excellent catalytic activity toward IO4â for AO7 degradation.â¢Dominant radical and potential mechanism in I-GAC/IO4â system were investigated.â¢Possible degradation pathway of AO7 in the I-GAC/IO4â system was proposed.
In this study, iodine-doped granular activated carbon (I-GAC) was prepared and subsequently applied to activate periodate (IO4â) to degrade organic contaminants at ambient temperature. The physicochemical properties of GAC and I-GAC were examined using scanning electron microscopy, N2 adsorption/desorption, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. No significant difference was observed between the two except for the existence of triiodide (I3â) and pentaiodide (I5â) on I-GAC. The catalytic activity of I-GAC towards IO4â was evaluated by the degradation of acid orange 7 (AO7), and superior catalytic performance was achieved compared with GAC. The effects of some influential parameters (preparation conditions, initial solution pH, and coexisting anions) on the catalytic ability were also investigated. Based on radical scavenging experiments, it appeared that IO3 was the predominant reactive species in the I-GAC/IO4â system. The mechanism underlying the enhanced catalytic performance of I-GAC could be explained by the introduction of negatively charged I3â and I5â into I-GAC, which induced positive charge density on the surface of I-GAC. This accelerated the interaction between I-GAC and IO4â, and subsequently mediated the increasing generation of iodyl radicals (IO3). Furthermore, a possible degradation pathway of AO7 was proposed according to the intermediate products identified by gas chromatography-mass spectrometry.
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