Soluble Complexes of Cobalt Oxide Fragments Bring the Unique CO2 Photoreduction Activity of a Bulk Material into the Flexible Domain of Molecular Science
| Autor: | Alexander I. Shames, Mark Baranov, Guanyun Zhang, Sebastian Kozuch, Alevtina Neyman, Fei Wang, Ira A. Weinstock, Juan M. Clemente-Juan, Josep Poblet, Nitai Leffler |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Valence (chemistry) Oxide Nanoparticle 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Tin oxide Photochemistry 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Coordination complex chemistry.chemical_compound Colloid and Surface Chemistry chemistry Molecular orbital 0210 nano-technology Cobalt oxide HOMO/LUMO |
| Zdroj: | Journal of the American Chemical Society. 143:20769-20778 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | The deposition of metal oxides is essential to the fabrication of numerous multicomponent solid-state devices and catalysts. However, the reproducible formation of homogeneous metal oxide films or of nanoparticle dispersions at solid interfaces remains an ongoing challenge. Here we report that molecular hexaniobate cluster anion complexes of structurally and electronically distinct fragments of cubic-spinel and monoclinic Co3O4 can serve as tractable yet well-defined functional analogues of bulk cobalt oxide. Notably, the energies of the highest-occupied and lowest-unoccupied molecular orbitals (HOMO and LUMO) of the molecular complexes, 1, closely match the valence- and conduction-band (VB and CB) energies of the parent bulk oxides. Use of 1 as a molecular analogue of the parent oxides is demonstrated by its remarkably simple deployment as a cocatalyst for direct Z-scheme reduction of CO2 by solar light and water. Namely, evaporation of an aqueous solution of 1 on TiO2-coated fluorinated tin oxide windows (TiO2/FTO), immersion in wet acetonitrile, and irradiation by simulated solar light under an atmosphere of CO2 give H2, CO, and CH4 in ratios nearly identical to those obtained using 20 nm spinel-Co3O4 nanocrystals, but 15 times more rapidly on a Co basis and more rapidly overall than other reported systems. Detailed investigation of the photocatalytic properties of 1 on TiO2/FTO includes confirmation of a direct Z-scheme charge-carrier migration pathway by in situ irradiated X-ray photoelectron spectroscopy. More generally, the findings point to a potentially important new role for coordination chemistry that bridges the conceptual divide between molecular and solid-state science. |
| Databáze: | OpenAIRE |
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