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Metal-doped carbon aerogels as catalysts during ozonation processes in aqueous solutions.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Sánchez-Polo, Manuel Rivera-Utrilla, José Gunten, Urs Von |
| Copyright Year | 2006 |
| Abstract | The efficiency of Co(II)-, Mn(II)-, and Ti(IV)-doped carbon aerogels for the transformation of ozone into (*)OH radicals was investigated. The carbon aerogels had a markedly acid surface character (pH(PZC approximately equal) congruent with 3-4) with very high surface oxygen concentrations (O approximately equal with 20%). X-ray photoelectron spectroscopy (XPS) analyses of the samples showed the oxidation state of the metals was +2 for Co and Mn and +4 for Ti. The presence of Mn(II)-doped carbon aerogel enhanced ozone transformation into (*)OH radicals, whereas the presence of Co(II) and Ti(IV) carbon aerogels presented no activity in this process. Moreover, it was observed that an increase in the concentration of Mn in the surface of the aerogel increases its efficiency to transform ozone into (*)OH radicals, with an Rct value ([OH]/[O(3)]) of 5.36 x 10(-8) for the aerogel doped with 16% of surface Mn(II) compared to an R(ct) of 2.68 x 10(-9) for conventional ozonation. Regardless of the aerogel used, XPS analysis of the ozonated aerogel samples showed an increase in the concentration of surface oxygen when the exposure to ozone was longer. However, presence of oxidized metal species after ozone treatment was only detected in the case of the Mn-doped aerogel, (Mn(III) and Mn(IV)). CO(2) activation of carbon aerogel produced a marked increase in its efficiency to transform ozone into (*)OH radicals compared with non-activated sample. The efficiency of Mn activated carbon aerogel to transform ozone into (*)OH radicals was greater than that of Witco commercial activated carbon or H(2)O(2) in the ozonation of water from Lake Zurich (Zurich, Switzerland). |
| Starting Page | 1 |
| Ending Page | 3 |
| Page Count | 3 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://hera.ugr.es/doi/16654778.pdf |
| PubMed reference number | 16970972v1 |
| Volume Number | 40 |
| Issue Number | 18 |
| Journal | Water research |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Activated Charcoal Diagnostic radiologic examination Hydroxyl Radical Manganese Metals Mn3+ Oxygen Ozone Solutions Titanium X-Ray Photoelectron Spectroscopy cobaltous cation oxidation |
| Content Type | Text |
| Resource Type | Article |
