BiVO4 Layer Formation via Microwave Chemical Bath Deposition

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Solution Overview

Problem

Existing methods for manufacturing BiVO4 thin films as photoelectrodes do not achieve sufficient performance for water electrolysis, requiring a more effective approach to produce high-performance BiVO4 layers.

Innovation Solution

A method involving microwave-activated chemical bath deposition (MW-CBD) of a substrate with a precursor solution containing vanadium and bismuth salts, followed by a sintering process, to form a BiVO4 layer with controlled phase ratios of zircon-structure tetragonal and scheelite-structure monoclinic phases, enhancing photocatalytic activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If fine BiVO4 powder is used to coat a substrate, then the thin film can be formed, but the photoelectrode performance is insufficient

Engineering Contradiction:
Improvethin film formationVSAvoidphotoelectrode performance
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention changes the manufacturing approach from coating pre-formed fine powder to in-situ formation using MW-CBD. By controlling parameters such as microwave power, precursor concentration, and deposition time, the method produces BiVO4 layers with superior crystallinity, phase composition (monoclinic phase dominance), and photoelectrode performance while maintaining thin film structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical coating process with a chemical deposition process activated by microwave energy. Instead of physically applying fine powder to the substrate, the method uses MW-CBD to chemically form BiVO4 directly on the substrate surface, resulting in better adhesion and photoelectrode performance

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If conventional coating methods are used, then the manufacturing process is simple, but the photocatalytic activity is insufficient

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidphotocatalytic activity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention employs a self-organizing chemical bath deposition process where BiVO4 crystals form automatically on the substrate surface under microwave irradiation. The precursor solution naturally deposits and crystallizes into a uniform layer without requiring complex coating equipment or manual operations, achieving both simplicity and high photocatalytic activity through the monoclinic phase structure

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method produces high-performance BiVO4 layers with improved photoresponsivity, enabling efficient water electrolysis at lower voltages and effective use as both photocatalysts and photoelectrodes.

Implementation Method 1

arranging a substrate heatable with microwaves in a precursor solution containing a vanadium salt and a bismuth salt, and forming a bismuth-vanadate layer on the substrate by microwave-activated chemical bath deposition (MW-CBD)

Methodology Applied
Scientific EffectMicrowave heating: Dielectric Heating

Implementation Method 2

forming a bismuth-vanadate layer on the substrate by microwave-activated chemical bath deposition (MW-CBD)

Methodology Applied
Scientific EffectChemical bath deposition: Chemical Vapour Deposition

Implementation Method 3

a sintering process is performed as necessary

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP2966042B1Bismuth-vanadate-laminate manufacturing method and bismuth-vanadate laminate
Publication Date: 2020.05.06 MITSUI CHEMICALS INC
  • EP2966042B1 patent drawingFigure 1(a)~1(b)
  • EP2966042B1 patent drawingFigure 2
  • EP2966042B1 patent drawingFigure 3A~3B

AI summary

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.