dc.contributor.author |
King’ondu, Cecil K. |
|
dc.contributor.author |
Opembe, Naftali |
|
dc.contributor.author |
Chen, Chun-hu |
|
dc.contributor.author |
Ngala, Katana |
|
dc.contributor.author |
Huang, Hui |
|
dc.contributor.author |
Iyer, Aparna |
|
dc.contributor.author |
Garcés, Hector F. |
|
dc.contributor.author |
Suib, Steven L. |
|
dc.date.accessioned |
2015-04-16T06:39:01Z |
|
dc.date.available |
2015-04-16T06:39:01Z |
|
dc.date.issued |
2011-01 |
|
dc.identifier.citation |
Advanced Functional Materials Volume 21, Issue 2, pages 312–323, January 21, 2011 |
en_US |
dc.identifier.uri |
http://onlinelibrary.wiley.com/doi/10.1002/adfm.201001020/full |
|
dc.identifier.uri |
http://repository.seku.ac.ke/handle/123456789/1165 |
|
dc.description |
DOI: 10.1002/adfm.201001020 |
en_US |
dc.description.abstract |
Self-assembled multidoped cryptomelane hollow microspheres with ultrafine particles in the size range of 4–6 nm, and with a very high surface area of 380 m2 g−1 have been synthesized. The particle size, morphology, and the surface area of these materials are readily controlled via multiple framework substitutions. The X-ray diffraction and transmission electron microscopy (TEM) results indicate that the as-synthesized multidoped OMS-2 materials are pristine and crystalline, with no segregated metal oxide impurities. These results are corroborated by infrared (IR) and Raman spectroscopy data, which show no segregated amorphous and/or crystalline metal impurities. The field-emission scanning electron microscopy (FESEM) studies confirm the homogeneous morphology consisting of microspheres that are hollow and constructed by the self-assembly of pseudo-flakes, whereas energy-dispersive X-ray (EDX) analyses imply that all four metal cations are incorporated into the OMS-2 structure. On the other hand, thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) demonstrate that the as-synthesized multidoped OMS-2 hollow microspheres are more thermally unstable than their single-doped and undoped counterparts. However, the in-situ XRD studies show that the cryptomelane phase of the multidoped OMS-2 hollow microspheres is stable up to about 450°C in air. The catalytic activity of these microspheres towards the oxidation of diphenylmethanol is excellent compared to that of undoped OMS-2 materials. |
en_US |
dc.language.iso |
en |
en_US |
dc.publisher |
Wiley |
en_US |
dc.subject |
catalysis |
en_US |
dc.subject |
doping |
en_US |
dc.subject |
manganese oxides |
en_US |
dc.subject |
hollow microstructures |
en_US |
dc.subject |
self-assembly |
en_US |
dc.subject |
structure–property relationships |
en_US |
dc.title |
Manganese Oxide Octahedral Molecular Sieves (OMS-2) multiple framework substitutions: A new route to OMS-2 particle size and morphology control |
en_US |
dc.type |
Article |
en_US |