Eutectic Photoanode Active Layer for Visible Light Absorption

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Solution Overview

Problem

Existing photoanodes for water photolysis in photoelectrochemical cells face challenges in absorbing visible light due to high band gaps, require chemical stability in aqueous solutions, and need to be cost-effective for industrial scale production, which oxide materials often fail to meet.

Innovation Solution

Employing eutectic materials such as nickel titanate-titanium oxide, tungsten trioxide-titanium oxide as the active layer in photoanodes, combined with a conductive contact layer and protective coatings, to enhance light absorption and chemical stability, and using a crystalline structure for improved performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oxide materials are used for photoanodes, then chemical stability is improved, but light absorption efficiency deteriorates due to high band gaps

Engineering Contradiction:
Improvechemical stabilityVSAvoidlight absorption efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs composite materials consisting of eutectic mixtures of metal oxides (such as NiTiO3-TiO2, WO3-TiO2, SrTiO3-TiO2, CoTiO3-TiO2, MnTiO3-TiO2) that combine the chemical stability of oxide materials with reduced band gaps. These eutectic composites enable effective visible light absorption while maintaining stability in aqueous electrolyte solutions, resolving the contradiction between chemical stability and light absorption efficiency.

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If materials with small band gaps are used, then light absorption efficiency is improved, but chemical stability deteriorates

Engineering Contradiction:
Improvelight absorption efficiencyVSAvoidchemical stability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The eutectic composite structure combines metal oxides with complementary properties, where the mixture achieves a lower effective band gap for visible light absorption while the oxide composition maintains chemical stability in aqueous environments. This composite approach allows simultaneous optimization of both light absorption and chemical stability.

Inventive Principle:
Principle #40Composite materials

3Productivity

If new materials are developed to meet performance requirements, then photoelectrochemical efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvephotoelectrochemical efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent utilizes eutectic compositions that can be synthesized through controlled changes in fabrication parameters such as sintering temperature and composition ratios. By adjusting these parameters, the material achieves optimal photoelectrochemical performance while maintaining compatibility with existing manufacturing processes for metal oxide materials.

Inventive Principle:
Principle #35Parameter changes

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

The eutectic materials demonstrate high photocurrent density and stability over time when exposed to electrolytes, effectively absorbing a wider range of electromagnetic radiation, including visible light, and are suitable for industrial-scale production.

Implementation Method 1

the process of the decomposition of water into oxygen and charges are generated which are transferred through an electric circuit to electrodes on which hydrogen is obtained, with the use of the electromagnetic (including solar) radiation energy

Methodology Applied
Scientific EffectPhotolysis: Photodissociation

Implementation Method 2

the absorption of the electromagnetic radiation and the production of the electron-hole pair of the electric charge carriers occurs

Methodology Applied
Scientific EffectAbsorption of electromagnetic radiation: Absorption (EM radiation)

Data Source

PatentEP2743946B1Use of Material, Especially an Eutectic One, as an Active Layer in an Electrode and an Electrode Comprising an Active Layer of Material, Especially an Eutectic One
Publication Date: 2017.10.11 INST TECH MATERIAL ELEKT
  • EP2743946B1 patent drawingFigure 1
  • EP2743946B1 patent drawingFigure 2~3
  • EP2743946B1 patent drawingFigure 4~5

AI summary

The invention relates to the use of a material selected from the group comprising: an eutectic, subeutectic, hypereutectic, monotectic, submonotectic, hypermonotectic, eutectoidal, subeutectoidal and hypereutectoidal material or a material being a product of a spinodal decomposition as an active layer in an electrode, especially in the photoanode for photoelectrochemical cells. The invention also includes an electrode, especially a photoanode for photoelectrochemical cells, comprising at least an active layer and an electric contact, optionally a contact layer situated between the active layer and the electric contact, characterised in that the active layer (1) made of a material selected from the group including: an eutectic, subeutectic, hypereutectic, monotectic, submonotectic, hypermonotectic, eutectoidal, subeutectoidal and hypereutectoidal material or a material being a product of spinodal decomposition.