Photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts
This disclosure relates to photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts. In certain embodiments, the disclosure relates to compositions comprising water, a complex of a tetra-metal oxide cluster and VW 9 O 34 ligands, and a photosensitizer. Typically, the metal oxide cluster is Co. In certain embodiments, the disclosure relates to electrodes and other devices comprising water oxidation catalysts disclosed herein and uses in generating fuels and electrical power from solar energy.
1. A composition comprising,
a) water,
b) a complex of a tetra-metal oxide cluster and VW 9 O 34 ligands, and
c) a photosensitizer.
2. The composition of claim 1 , wherein metal is Co.
3. The composition of claim 1 , wherein the photosensitizer is a ruthenium complex, quantum dot, or other metallic nanostructure.
4. The composition of claim 3 , wherein the ruthenium complex comprises a tris-bidentate ligand complex.
5. The composition of claim 1 , further comprising a compound that acts as an electron acceptor.
6. The composition of claim 5 , wherein the electron acceptor is persulfate.
7. An electrochemical cell comprising:
a) a first electrode,
b) a photosensitizer,
c) a complex of a tetra-metal oxide cluster and VW 9 O 34 ligands, and
d) a second electrode.
8. The electrochemical cell of claim 7 , wherein metal is Co.
9. The electrochemical cell of claim 7 , wherein the first electrode comprises a
semiconductor
metal oxide.
10. The electrochemical cell of claim 9 , wherein the semiconductor metal oxide comprises TiO 2 , Fe 2 O 3 , or WO 3 .
11. The electrochemical cell of claim 7 , wherein the second electrode comprises a water reduction catalyst.
12. The electrochemical cell of claim 7 , wherein the photosensitizer is ruthenium complex, quantum dot, nanostructure, or multicomponent nanostructure.
13. The electrochemical cell of claim 12 , wherein the ruthenium complex is a tris-bidentate ligand complex.
14. A method of oxidizing water comprising exposing a composition comprising:
a) water,
b) a complex of a tetra-metal oxide cluster and VW 9 O 34 ligands, and
c) a photosensitizer,
to light under conditions such that oxygen is formed.
15. The method of claim 14 , wherein oxygen and hydrogen are formed.
16. A process for preparing a complex of a tetra-metal oxide cluster and VW 9 O 34 ligands comprising mixing M(NO 3 ) 2 , WO 4 2− salts and VO 3 − salts, under conditions such that of a tetra-metal oxide cluster and VW 9 O 34 ligands is formed wherein M is a metal.
17. The process of claim 16 , wherein M is Co.