US4090933A
Expired / Lapsed
US
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Photoelectrolysis of water by solar radiation
Assignee: Honeywell International Inc
•
Filing: 1976-11-26
•
Granted: 1978-05-23
•
Expires: 1996-11-26
Abstract
Abstract Photoelectrolysis of water by solar radiation to produce hydrogen is achieved using semiconducting thin film electrodes. The cell comprises (a) an anodic electrode comprising at least one thin n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate; (b) a cathodic counter-electrode comprising at least one thin p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is supported on a supporting conductive substrate, the p-type layer adjacent the n-type layer being such that incident solar radiation impinges substantially simultaneously on both the n- and p-type electrodes; (c) means for retaining an electrolyte in contact with the exposed surfaces of the n- and p-type semiconducting electrodes; (d) external bias means between the electrode and the counter-electrode for biasing the cell with from 0 to about 1 V; and (e) means for collecting hydrogen and any oxidation products produced.
Inventors
- 👤 Arthur J. Nozik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:35
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/20; C; C25; C25B; C25B1/00; C25B1/50; C25B1/55; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/36; Y02P; Y02P20/00; Y02P20/10; Y02P20/129; Y02P20/133; Y10; Y10S; Y10S204/00; Y10S204/03
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
168 words
A photoelectrolysis cell for producing hydrogen using solar radiation comprising (a) an anodic electrode comprising at least one n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate; (b) a cathodic counter-electrode comprising at least one p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate, the p-type layer adjacent the n-type layer, with the n-type and p-type layers being either coplanar or disposed semicylindrically on an elongated, cylindrical substrate such that incident solar radiation impinges substantially simultaneously on both the n-type and p-type electrodes; (c) means for retaining an electrolyte in contact with the exposed surfaces of the n- and p-type semiconducting electrodes; (d) external bias means between the electrode and the counter-electrode for anodically biasing the anodic electrode relative to the cathodic counter-electrode with 0 to about 1 V; and (e) means for collecting hydrogen produced at the anodic electrode.
Claim 2
Dependent Claim
168 words
A photoelectrolysis cell for producing hydrogen using solar radiation comprising (a) an anodic electrode comprising at least one n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate; (b) a cathodic counter-electrode comprising at least one p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate, the p-type layer adjacent the n-type layer, with the n-type and p-type layers being either coplanar or disposed semicylindrically on an elongated, cylindrical substrate such that incident solar radiation impinges substantially simultaneously on both the n-type and p-type electrodes; (c) means for retaining an electrolyte in contact with the exposed surfaces of the n- and p-type semiconducting electrodes; (d) external bias means between the electrode and the counter-electrode for anodically biasing the anodic electrode relative to the cathodic counter-electrode with 0 to about 1 V; and (e) means for collecting hydrogen produced at the anodic electrode.
Claim 3
Dependent Claim
18 words
The cell of claim 1 further including means for collecting any oxidation products produced at the anodic electrode.
Claim 4
Dependent Claim
78 words
The cell of claim 1 in which the anodic electrode comprises a suitably doped n-type composition selected from the group consisting of TiO 2 , In 2 O 3 , SnO 2 , GaAs, GaP, WO 3 , SiC, Fe 2 O 3 , CdS, CuInS 2 , Si and MTiO 3 , where M is at least one element selected from the group consisting of La, Ba, Sr, the rare earth elements and the transition metal elements.
Claim 5
Dependent Claim
19 words
The cell of claim 3 in which the anodic electrode comprises a semiconducting layer of n-type TiO 2 .
Claim 6
Dependent Claim
37 words
The cell of claim 1 in which the counter-electrode comprises a suitably doped p-type composition selected from the group consisting of GaP, GaAs, Si, Cu 2 S, Cu 2 O, InP, ZnSe, CdTe and CuInS 2 .
Claim 7
Dependent Claim
16 words
The cell of claim 5 in which the counter-electrode comprises a semiconducting layer of p-type GaP.
Claim 8
Dependent Claim
39 words
The cell of claim 1 in which the relative areas of the n- and p-type semiconducting electrodes are such that substantially equal rates of photon absorption are produced in each electrode when the cell is illuminated with solar radiation.
Claim 9
Dependent Claim
13 words
The cell of claim 1 in which the supporting conductive substrates are metallic.
Claim 10
Dependent Claim
28 words
The cell of claim 8 in which each of the metallic supporting conductive substrates in contact with the respective n- and p-type semiconducting electrodes comprises an ohmic contact.
Claim 11
Dependent Claim
26 words
The cell of claim 1 in which the electrode and counter-electrode are in the form of films of about 500 A to 10 μm in thickness.
Claim 12
Dependent Claim
24 words
The cell of claim 1 further including means for directing solar radiation onto at least a portion of at least one of the electrodes.
Claim 13
Dependent Claim
14 words
The cell of claim 1 in which the n-type and p-type layers are coplanar.
Claim 14
Dependent Claim
18 words
The cell of claim 12 in which the n-type and p-type layers are separated by an insulating section.
Claim 15
Dependent Claim
20 words
The cell of claim 1 in which the n-type and p-type layers are disposed semicylindrically on an elongated, cylindrical substrate.
Claim 16
Dependent Claim
18 words
The cell of claim 14 in which the n-type and p-type layers are separated by an insulating section.
Claim 17
Dependent Claim
159 words
A process for producing hydrogen using solar radiation comprising (a) exposing to solar radiation an anodic electrode in contact with an electrolyte in turn having a cathodic counter-electrode in contact therewith, the electrode comprising at least one n-type semiconducting layer which has a bandgap ranging from about 0.4 to 4.0 eV and which is disposed on a supporting conductive substrate, and the counter-electrode comprising at least one p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate, the p-type layer adjacent the n-type layer, with the n-type and p-type layers being either coplanar or disposed semicylindrically on an elongated, cylindrical substrate, such that incident solar radiation impinges substantially simultaneously on both the n- and p-type semiconducting electrodes; (b) applying an anodic bias to the anodic electrode relative to the cathodic counter-electrode of 0 to about 1 V; and (c) collecting hydrogen produced at the cathodic counter-electrode.
Claim 18
Dependent Claim
159 words
A process for producing hydrogen using solar radiation comprising (a) exposing to solar radiation an anodic electrode in contact with an electrolyte in turn having a cathodic counter-electrode in contact therewith, the electrode comprising at least one n-type semiconducting layer which has a bandgap ranging from about 0.4 to 4.0 eV and which is disposed on a supporting conductive substrate, and the counter-electrode comprising at least one p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and which is disposed on a supporting conductive substrate, the p-type layer adjacent the n-type layer, with the n-type and p-type layers being either coplanar or disposed semicylindrically on an elongated, cylindrical substrate, such that incident solar radiation impinges substantially simultaneously on both the n- and p-type semiconducting electrodes; (b) applying an anodic bias to the anodic electrode relative to the cathodic counter-electrode of 0 to about 1 V; and (c) collecting hydrogen produced at the cathodic counter-electrode.
Claim 19
Dependent Claim
16 words
The process of claim 16 further including collecting any oxidation products produced at the anodic electrode.
Claim 20
Dependent Claim
80 words
The process of claim 16 in which the anodic electrode comprises at least one suitably doped n-type composition selected from the group consisting of TiO 2 , In 2 O 3 , SnO 2 , GaAs, GaP, WO 3 , SiC, Fe 2 O 3 , CdS, CuInS 2 , Si and MTiO 3 , where M is at least one element selected from the group consisting of La, Ba, Sr, the rare earth elements and the transition metal elements.
Claim 21
Dependent Claim
19 words
The process of claim 18 in which the anodic electrode comprises a semiconducting layer of n-type TiO 2 .
Claim 22
Dependent Claim
37 words
The process of claim 16 in which the counter-electrode comprises a suitably doped p-type composition selected from the group consisting of GaP, GaAs, Si, Cu 2 S, Cu 2 O, InP, ZnSe, CdTe and CuInS 2 .
Claim 23
Dependent Claim
16 words
The process of claim 20 in which the counter-electrode comprises a semiconducting layer of p-type GaP.
Claim 24
Dependent Claim
40 words
The process of claim 16 in which the relative areas of the n- and p-type semiconducting electrodes are adjusted such that substantially equal rates of photon absorption are produced in each electrode when the electrodes are illuminated with solar radiation.
Claim 25
Dependent Claim
13 words
The process of claim 16 in which the supporting conductive substrates are metallic.
Claim 26
Dependent Claim
28 words
The process of claim 23 in which each of the metallic supporting conductive substrates forms an ohmic contact to each of the respective n- and p-type semiconducting electrodes.
Claim 27
Dependent Claim
28 words
The process of claim 16 in which the electrolyte comprises an aqueous solution having a specific conductivity of at least about 10 -3 ohm -1 cm -1 .
Claim 28
Dependent Claim
13 words
The process of claim 16 in which the electrolyte includes a photosensitive dye.
Claim 29
Dependent Claim
26 words
The process of claim 16 in which the electrode and counter-electrode are in the form of films of about 500 A to 10 μm in thickness.
Claim 30
Dependent Claim
169 words
A photoelectrolysis cell for producing hydrogen using solar radiation comprising (a) an anodic electrode comprising at least one porous n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV; (b) a cathodic counter-electrode comprising at least one porous p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV, with the n- and p-type layers either having an electrical conductivity of at least about 1 ohm -1 cm -1 or supported on electrically conducting porous substrates; (c) an opaque solid polymer electrolyte film interposed between the n-type and p-type semiconducting electrodes; (d) means for retaining water in contact with the exposed surfaces of the n- and p-type semiconducting electrodes; (e) external bias means between the electrode and the counter-electrode for anodically biasing the anodic electrode relative to the cathodic counter-electrode with 0 to about 1 V; (f) means for directing the solar radiation onto at least a portion of the electrodes; and (g) means for collecting hydrogen produced at the cathodic counter-electrode.
Claim 31
Dependent Claim
169 words
A photoelectrolysis cell for producing hydrogen using solar radiation comprising (a) an anodic electrode comprising at least one porous n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV; (b) a cathodic counter-electrode comprising at least one porous p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV, with the n- and p-type layers either having an electrical conductivity of at least about 1 ohm -1 cm -1 or supported on electrically conducting porous substrates; (c) an opaque solid polymer electrolyte film interposed between the n-type and p-type semiconducting electrodes; (d) means for retaining water in contact with the exposed surfaces of the n- and p-type semiconducting electrodes; (e) external bias means between the electrode and the counter-electrode for anodically biasing the anodic electrode relative to the cathodic counter-electrode with 0 to about 1 V; (f) means for directing the solar radiation onto at least a portion of the electrodes; and (g) means for collecting hydrogen produced at the cathodic counter-electrode.
Claim 32
Dependent Claim
18 words
The cell of claim 28 further including means for collecting any oxidation products produced at the anodic electrode.
Claim 33
Dependent Claim
24 words
The cell of claim 28 further including means for directing solar radiation onto at least a portion of at least one of the electrodes.
Claim 34
Dependent Claim
26 words
The cell of claim 28 in which the n- and p-type layers have an electrical conductivity of at least about 1 ohm -1 cm -1 .
Claim 35
Dependent Claim
18 words
The cell of claim 28 in which the n- and p-type layers are supported on electrically conducting substrates.
Claim 36
Dependent Claim
78 words
The cell of claim 28 in which the anodic electrode comprises a suitably doped n-type composition selected from the group consisting of TiO 2 , In 2 O 3 , SnO 2 , GaAs, GaP, WO 3 , SiC, Fe 2 O 3 , CdS, CuInS 2 , Si, and MTiO 3 , where M is at least one element selected from the group consisting of La, Ba, Sr, the rare earth elements and the transition metal elements.
Claim 37
Dependent Claim
18 words
The cell of claim 33 in which the electrode comprises a semiconductor layer of n-type TiO 2 .
Claim 38
Dependent Claim
37 words
The cell of claim 28 in which the counter-electrode comprises a suitably doped p-type composition selected from the group consisting of GaP, GaAs, Si, Cu 2 S, Cu 2 O, InP, ZnSe, CdTe and CuInS 2 .
Claim 39
Dependent Claim
16 words
The cell of claim 35 in which the counter-electrode comprises a semiconducting layer of p-type GaP.
Claim 40
Dependent Claim
38 words
The cell of claim 28 in which the relative areas of n- and p-type semiconducting electrodes are such that substantially equal rates of photon absorption are produced in each electrode when the cell is illuminated with solar radiation.
Claim 41
Dependent Claim
13 words
The cell of claim 28 in which the supporting conductive substrates are metallic.
Claim 42
Dependent Claim
28 words
The cell of claim 38 in which each of the metallic supporting conductive substrates in contact with the respective n- and p-type semiconducting electrodes comprises an ohmic contact.
Claim 43
Dependent Claim
26 words
The cell of claim 28 in which the electrode and counter-electrode are in the form of films of about 500 A to 10 μm in thickness.
Claim 44
Dependent Claim
145 words
A process for producing hydrogen using solar radiation comprising (a) exposing to solar radiation an anodic electrode in contact with an electrolyte in turn having a cathodic counter-electrode in contact therewith, the electrode comprising at least one porous n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and the counter-electrode comprising at least one porous p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV, with the n- and p-type layers either having an electrical conductivity of at least about 1 ohm -1 cm -1 or supported on electrically conducting porous substrates, the p-type layer separated from the n-type layer by an opaque solid polymer electrolyte film; (b) applying an anodic bias to the anodic electrode relative to the cathodic counter-electrode of 0 to about 1 eV; and (c) collecting hydrogen produced at the cathodic counter-electrode.
Claim 45
Dependent Claim
145 words
A process for producing hydrogen using solar radiation comprising (a) exposing to solar radiation an anodic electrode in contact with an electrolyte in turn having a cathodic counter-electrode in contact therewith, the electrode comprising at least one porous n-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV and the counter-electrode comprising at least one porous p-type semiconducting layer which has a bandgap ranging from about 0.5 to 4.0 eV, with the n- and p-type layers either having an electrical conductivity of at least about 1 ohm -1 cm -1 or supported on electrically conducting porous substrates, the p-type layer separated from the n-type layer by an opaque solid polymer electrolyte film; (b) applying an anodic bias to the anodic electrode relative to the cathodic counter-electrode of 0 to about 1 eV; and (c) collecting hydrogen produced at the cathodic counter-electrode.
Claim 46
Dependent Claim
16 words
The process of claim 41 further including collecting any oxidation products produced at the anodic electrode.
Claim 47
Dependent Claim
79 words
The process of claim 41 in which the electrode comprises at least one suitably doped n-type composition selected from the group consisting of TiO 2 , In 2 O 3 , SnO 2 , GaAs, GaP, WO 3 , SiC, Fe 2 O 3 , CdS, CuInS 2 , Si and MTiO 3 , where M is at least one element selected from the group consisting of La, Ba, Sr, the rare earth elements and the transition metal elements.
Claim 48
Dependent Claim
18 words
The process of claim 43 in which the electrode comprises a semiconducting layer of n-type TiO 2 .
Claim 49
Dependent Claim
37 words
The process of claim 41 in which the counter-electrode comprises a suitably dopes p-type composition selected from the group consisting of GaP, GaAs, Si, Cu 2 S, Cu 2 O, InP, ZnSe, CdTe and CuInS 2 .
Claim 50
Dependent Claim
16 words
The process of claim 45 in which the counter-electrode comprises a semiconducting layer of p-type GaP.
Claim 51
Dependent Claim
40 words
The process of claim 41 in which the relative areas of the n- and p-type semiconducting electrodes are adjusted such that substantially equal rates of photon absorption are produced in each electrode when the electrodes are illuminated with solar radiation.
Claim 52
Dependent Claim
13 words
The process of claim 41 in which the supporting conductive substrates are metallic.
Claim 53
Dependent Claim
28 words
The process of claim 48 in which each of the metallic supporting conductive substrates forms an ohmic contact to each of the respective n- and p-type semiconducting electrodes.
Claim 54
Dependent Claim
26 words
The process of claim 41 in which the solid polymer electrolyte has a specific conductivity of at least about 10 -3 ohm -1 cm -1 .
Claim 55
Dependent Claim
26 words
The process of claim 41 in which the electrode and counter-electrode are in the form of films of about 500 A to 10 μm in thickness.
References Cited (Backward Citations)
US3925212A
Cited
US3989542A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |