Photosensitive cell for the decomposition of water

• US 4,595,568 A
• Filed: 06/20/1983
• Issued: 06/17/1986
• Est. Priority Date: 06/28/1982
• Status: Expired due to Fees

• Current Assignee: Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique
• Inventors: Van Damme, Henri, Fripiat, Jose J., Marceau, Philippe, Francois, Obrecht, Nijs, Hubert
• Primary Examiner(s): Lechert, Jr., Stephen J.
• Assistant Examiner(s): Locker, Howard J.
• Application Number:
  US06/505,909
• Time in Patent Office: 1,093 Days
• Field of Search: 422/186.30, 422/186, 204/302, 204/DIG. 6, 204/157.1 R, 204/129, 204/278, 423/648 R, 429/111
• US Class Current: 422/186
• CPC Class Codes: C01B 3/042 Decomposition of water
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

The invention relates to a photosensitive cell for the decomposition of water of the type formed by an aqueous medium containing a photosensitizer positively charged both in the reduced state and in the oxidized state, an acceptor, an oxygen forming catalyst and a hydrogen forming catalyst.

The cell according to the invention is characterized in that each of the two catalysts is fixed to a different support and in that the support of the oxygen forming catalyst is formed by a first, negative charge carrying colloid while the support of the hydrogen forming catalyst is formed by a second, positive charge carrying colloid.

Claims

1. A photosensitive cell for the decomposition of water, comprising an aqueous medium containing a photosensitizer positively charged both in the reduced state and in the oxidised state, an acceptor, an oxygen-forming catalyst, a first support to which said oxygen-forming catalyst fixed and formed by a first, negative-charge-carrying colloid of large-surface tectosilicates and phyllosilicates, which as a result of isomorphic substitutions in the crystal lattice carry a permanent negative charge, a hydrogen-forming catalyst, and a second support to which said hydrogen-forming catalyst is fixed and formed by a second, positive-charge-carrying colloid of colloidal silica modified by a pH adjustment, below the zero charge point, hydrotalcites, or a mixed colloidal hydroxide of Al³⁺ and Eu³⁺ or In³⁺.

2. A cell as claimed in claim 1, wherein said tectosilicates and phyllosilicates are zeolite, montmorillonite, hectorite or sepiolite.

3. A cell as claimed in claim 1, wherein the acceptor is a molecular compound which is neutral or negatively charged in the reduced state selected from neutral viologens.

4. A cell as claimed in claim 1, wherein the acceptor is in the form of Eu³⁺ or IN³⁺ ions directly incorporated by coprecipitation in the second, positive-charge-carrying colloid.

5. A cell as claimed in claim 1, wherein the Eu³⁺ or IN³⁺ ions are incorporated in the second colloid in a proportion of from 1 to 5%, expressed as a molar fraction.

6. A cell as claimed in claim 1, wherein the first, negative-charge-carrying colloid is formed by sepiolite to which ruthenium oxide is fixed and to which the positively charged photosensitizer is fixed by an ionic bond and the second, positive-charge-carrying colloid is formed by a mixed colloidal hydroxide of Al³⁺ and Eu³⁺ or IN³⁺ on which Pt is deposited.

7. A cell as claimed in claim 1, wherein the photosensitizer is the complex tris-(2,2'"'"'-bipyridine) ruthenium (II).

8. A cell as in claim 1 wherein the oxygen forming catalysts are oxides of transition metals.

9. A cell as in claim 8, wherein the hydrogen forming catalyst is platinum, gold or silver, in metallic, particulate form.

10. A cell as claimed in claim 3, wherein said neutral viologens are 4,4'"'"'-bipyridinium propyl silfonate, neutral europium (III) chelates, such as Eu (III) tris-salicylate, Eu (III) nitrilotriacetate, Eu (III) tris-acetyl acetonate, Eu (III) tris-oxalate, neutral indium (III) complexes or neutral chromium (III) complexes.

11. A cell as in claim 8, wherein said oxides of transition metals are:

RuO₂, IrO₂, NiO, O₅ O₂ or mixed oxides thereof.