Bismuth-vanadate-laminate manufacturing method and bismuth-vanadate laminate

Patent metadata

Field	Value
Publication number	US-10320005-B2
Application number	US-201414772643-A
Country	US
Kind code	B2
Filing date	Mar 4, 2014
Priority date	Mar 7, 2013
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A new BiVO4-laminate manufacturing method and BiVO4 laminate are provided. A bismuth-vanadate laminate is manufactured as follows: a substrate that can be heated by microwaves is disposed inside a precursor solution containing a vanadium salt and a bismuth salt, microwave-activated chemical bath deposition (MW-CBD) is used to form a bismuth-vanadate layer on the substrate, and a firing process is performed as necessary. A bismuth-vanadate laminate manufactured in this way is suitable for use as a photocatalyst or photoelectrode.

First claim

The invention claimed is:

1. A manufacturing method for forming two bismuth-vanadate layers on a substrate, the method comprising:
arranging the substrate in a precursor solution containing a vanadium salt and a bismuth salt,
heating the substrate arranged in the precursor solution by irradiating with microwave radiation thereby forming a first bismuth-vanadate layer on the substrate, and
forming a second bismuth-vanadate layer on the first bismuth-vanadate layer by coating and sintering the precursor solution on the first bismuth-vanadate layer,
wherein ratios of a zircon-structure tetragonal phase and a scheelite-structure monoclinic phase in a crystal phase of the first bismuth-vanadate layer are controlled by controlling at least one of (a) a sintering temperature and (b) a sintering time in the sintering.

2. The manufacturing method according to claim 1 , wherein
the crystal phase of the first bismuth-vanadate layer is a zircon-structure tetragonal phase, and a crystal phase of the second bismuth-vanadate layer is a scheelite-structure monoclinic phase.

3. The manufacturing method according to claim 1 , wherein irradiation power of the microwave radiation is from 100 to 500 W.

4. The manufacturing method according to claim 3 , wherein irradiation time of the microwave radiation is from 1 to 30 minutes.

5. The manufacturing method according to claim 1 , wherein the sintering is performed at a temperature of 100 to 550° C. for a duration of 0.5 to 5 hours.

6. The manufacturing method according to claim 1 , wherein the substrate is a glass or a resin substrate including a conductive film.

7. The manufacturing method according to claim 6 , wherein the conductive film is selected from the group consisting of tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), fluorine-doped in tin-oxide (FTO), and aluminum-doped zinc oxide (AZO).

Assignees

• Univ Tokyo Science Found
• Mitsui Chemicals Inc
• Japan Tech Research Association Of Artificial Photosynthetic Chemical Process

Inventors

• Kudo Akihiko
• Jia Qingxin
• Iwase Akihide

Classifications

• C23C18/143

  Radiation by light, e.g. photolysis or pyrolysis · CPC title

• B01J37/346

  of microwave energy · CPC title

• B01J23/14 Primary

  of germanium, tin or lead · CPC title

• B01J23/22

  Vanadium · CPC title

• C23C18/1216

  Metal oxides (C23C18/1212 takes precedence) · CPC title