Catalyst-free synthesis of transparent, mesoporous diamond monoliths from periodic mesoporous carbon CMK-8
We report on the synthesis of optically transparent, mesoporous, monolithic diamond from periodic mesoporous carbon CMK-8 at a pressure of 21 GPa. The phase transformation is already complete at a mild synthesis temperature of 1,300 °C without the need of a catalyst. Surprisingly, the diamond is obt...
Saved in:
Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 107; no. 31; pp. 13593 - 13596 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
03.08.2010
National Acad Sciences |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | We report on the synthesis of optically transparent, mesoporous, monolithic diamond from periodic mesoporous carbon CMK-8 at a pressure of 21 GPa. The phase transformation is already complete at a mild synthesis temperature of 1,300 °C without the need of a catalyst. Surprisingly, the diamond is obtained as a mesoporous material despite the extreme pressure. X-ray diffraction, SEM, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, and Z-contrast experiments suggest that the mesoporous diamond is composed of interconnected diamond nanocrystals having diameters around 5–10 nm. The Brunauer Emmett Teller surface area was determined to be 33 m² g⁻¹ according Kr sorption data. The mesostructure is diminished yet still detectable when the diamond is produced from CMK-8 at 1,600 °C and 21 GPa. The temperature dependence of the porosity indicates that the mesoporous diamond exists metastable and withstands transformation into a dense form at a significant rate due to its high kinetic inertness at the mild synthesis temperature. The findings point toward ultrahard porous materials with potential as mechanically highly stable membranes. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Author contributions: K.L. designed research; L.Z., P.M., and N.C. performed research; L.Z., P.M., N.C., Y.F., H.-K.M., and K.L. analyzed data; and L.Z. and K.L. wrote the paper. Contributed by Ho-Kwang Mao, June 16, 2010 (sent for review March 1, 2010) |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.1006938107 |