Abstract Details
| Co3O4 Nanoclusters on Mesoporous Silica Support as Catalysts for Water Oxidation Driven by Visible Light | |
|---|---|
| Abstract ID | MAT-06 |
| Presenter | Feng Jiao |
| Presentation Type | Poster |
| Full Author List | F. Jiao (1) , H. M. Frei (1) |
| Affiliations | (1) Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA |
| Category | Materials Science |
| Abstract | The development of integrated artificial photosynthetic systems for the direct conversion of carbon dioxide and water to fuel depends on the availability of efficient and robust catalysts for the chemical transformations. For the water oxidation half reaction, it is still a difficult challenge to find an efficient catalyst based on abundant first row transition metals. Hence, we demonstrated Co oxide nanoclusters as good candidates for water oxidation catalysts under mild pH and temperature conditions.
Co oxide nanoclusters have been successfully synthesized inside a mesoporous silica SBA-15 channels by wet impregnation method. TEM analysis confirms that Co3O4 nanoclusters are formed inside the mesoporous support with a diameter of ~30 nm. Extended X-ray absorption fine structure (EXAFS) data were collected for bulk and nanoclusters Co3O4. There is good agreement between the first shell Co-O bond lengths for the nanoclusters and the bulk phase. Considering the next nearest neighbor Co-Co distances, peaks for the Co3O4 nanoclusters are weaker but several peaks are again apparent corresponding to the different Co-Co distances observed for the bulk material, suggesting the presence of nanocrystallites of Co3O4.
Preliminary results of photochemical water oxidation experiments confirm that Co3O4 nanoclusters exhibit superior water oxidation activity, due to the high surface area of the nanoclusters. Mechanistic studies are in progress.
In conclusion, Co3O4 nanoclusters have been prepared in a mesoporous silica support (SBA-15). The structure of the materials was confirmed by TEM and EXAFS analysis. Oxygen evolution experiments demonstrated that nanoclusters have superior photocatalytic activity compared with its bulk phase. |
| Footnotes | |
| Funding Acknowledgement | This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences of the U.S. Department of Energy under Contract DE-AC03-76SF00098. Portions of this research were carried out at the Stanford Synchrotron Radiation Laboratory, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. The SSRL Structural Molecular Biology Program is supported by the Department of Energy, Office of Biological and Environmental Research, and by the National Institutes of Health, National Center for Research Resources, Biomedical Technology Program. |