Photochemical electrode and oxygen evolution device

Patent metadata

Field	Value
Publication number	US-10858745-B2
Application number	US-201715685469-A
Country	US
Kind code	B2
Filing date	Aug 24, 2017
Priority date	Aug 31, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A photochemical electrode includes: an optical absorption layer; a catalyst layer for oxygen evolution reaction over the optical absorption layer; and a conducting layer over the catalyst layer. A valance band maximum of the catalyst layer is higher than a valance band maximum of the optical absorption layer. A work function of the conducting layer is larger than a work function of the catalyst layer.

First claim

What is claimed is:

1. A photochemical electrode comprising:
an optical absorption layer;
a PrNiO 3 layer which is a catalyst layer for oxygen evolution reaction over the optical absorption layer; and
a porous Au layer over the PrNiO 3 layer, wherein:
a valance band maximum of the catalyst layer is higher than a valance band maximum of the optical absorption layer; and
a work function of the porous Au layer is larger than a work function of the PrNiO 3 layer.

2. The photochemical electrode according to claim 1 , further comprising an optical transmission layer in type II heterojunction with the optical absorption layer, wherein:
the optical absorption layer is over the optical transmission layer; and
the valence band maximum of the optical absorption layer is higher than a valance band maximum of the optical transmission layer.

3. The photochemical electrode according to claim 2 , wherein a band gap of the optical transmission layer is 3 eV or more.

4. The photochemical electrode according to claim 2 , wherein the optical transmission layer contains SrTiO 3 , (La 0.3 Sr 0.7 )(Al 0.65 Ta 0.35 )O 3 , LaAlO 3 , MgO, NdGaO 3 , or DyScO 3 .

5. The photochemical electrode according to claim 1 , wherein a band gap of the optical absorption layer is 3 eV or less.

6. The photochemical electrode according to claim 5 , wherein the band gap of the optical absorption layer is not less than 1 eV nor more than 3 eV.

7. The photochemical electrode according to claim 1 , wherein the optical absorption layer contains an oxide including a perovskite structure.

8. The photochemical electrode according to claim 1 , wherein the optical absorption layer contains an oxide that is BiFeO 3 .

9. An oxygen evolution device comprising:
an aqueous electrolyte;
a photochemical electrode in the aqueous electrolyte; and
a cathode electrode in the aqueous electrolyte,
wherein the photochemical electrode comprises:
an optical absorption layer;
a PrNiO 3 layer which is a catalyst layer for oxygen evolution reaction over the optical absorption layer; and
a porous Au layer over the catalyst layer, wherein:
a valance band maximum of the PrNiO 3 layer is higher than a valance band maximum of the optical absorption layer; and
a work function of the porous Au layer is larger than a work function of the PrNiO 3 layer.

10. The photochemical electrode according to claim 1 , wherein the optical absorption layer is in contact with one surface of the PrNiO 3 layer, and the porous Au layer is in contact with the other surface of the PrNiO 3 layer.

11. The oxygen evolution device according to claim 9 , wherein of the optical absorption layer, the PrNiO 3 layer and the porous Au layer, only the porous Au layer is in contact with the aqueous electrolyte.

Assignees

• Fujitsu Ltd

Inventors

• Baniecki John David
• Aso Hiroyuki
• Imanaka Yoshihiko

Classifications

• C25B11/069 Primary

  consisting of at least one single element and at least one compound; consisting of two or more compounds · CPC title

• C25B1/55

  Photoelectrolysis · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C01G23/006

  Alkaline earth titanates · CPC title

• C23C14/3485

  using pulsed power to the target · CPC title