Self-Cleaning Coating Plasmonic Nanoparticles

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current self-cleaning coatings based on TiO2 have limitations due to high recombination rates and a narrow absorption spectrum, which reduces their photocatalytic activity and effectiveness in degrading pollutants, especially under visible light conditions, and the integration of metal nanoparticles is not stable or efficient.

Innovation Solution

Embedding plasmonic nanoparticles within the TiO2 matrix during the sol-gel synthesis process to enhance photocatalytic activity, extend the absorption spectrum to include visible light, and improve stability by reducing nanoparticle detachment and chemical reactivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If metal nanoparticles are used to extend absorption range, then visible light absorption is improved, but nanoparticle detachment and chemical reactivity increase

Engineering Contradiction:

Improvevisible light absorptionVSAvoidnanoparticle stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent embeds metal nanoparticles within the TiO2 matrix structure, nesting the nanoparticles inside the photocatalytic material rather than having them on the surface. This nesting approach extends visible light absorption through the plasmonic effect of embedded metal nanoparticles while protecting them from detachment and environmental reactions, as they are incorporated into the bulk material structure.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent creates a composite material system where metal nanoparticles are integrated with TiO2 to form a unified photocatalytic structure. This composite approach combines the plasmonic properties of metal nanoparticles for visible light absorption with the photocatalytic activity of TiO2, while the composite structure itself provides stability and prevents nanoparticle detachment.

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If metal nanoparticles are added to extend absorption, then photocatalytic activity under visible light improves, but surface area for degradation reactions decreases

Engineering Contradiction:

Improvephotocatalytic activity under visible lightVSAvoidsurface area

Core Design Contradiction:

Use of energy by moving objectVSArea of stationary object

Solution Approach 1:

By nesting metal nanoparticles within the TiO2 matrix rather than placing them on the surface, the patent preserves the full surface area of TiO2 for degradation reactions. The embedded nanoparticles extend visible light absorption through the bulk material via plasmonic effects, while the TiO2 surface remains fully available for photocatalytic reactions.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Productivity

If TiO2 is used as photocatalyst, then UV light degradation is effective, but visible light (50% of solar spectrum) remains unused

Engineering Contradiction:

Improvepollutant degradation efficiencyVSAvoidvisible light energy

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent creates a composite of TiO2 with embedded metal nanoparticles that combines the UV photocatalytic activity of TiO2 with the visible light plasmonic absorption of metal nanoparticles. This composite structure enables utilization of both UV and visible portions of the solar spectrum for photocatalytic degradation, converting previously wasted visible light energy into useful photocatalytic activity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the optical parameters of TiO2 by embedding metal nanoparticles that introduce plasmonic resonance in the visible range. This parameter change extends the absorption spectrum from UV-only to include visible light, enabling the material to utilize a broader range of solar energy for photocatalytic reactions.

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 embedded nanoparticles increase photocatalytic activity by reducing recombination rates and allowing for efficient degradation of pollutants under both UV and visible light, while maintaining transparency and stability of the coating.

Implementation Method 1

The metal nanoparticles may improve the photocatalytic properties of the underlying material by extending the effective absorption range of the TiO2

Methodology Applied

Scientific EffectLocalized surface plasmon resonance:

Implementation Method 2

TiO2 is very interesting for green chemistry as it can degrade e.g. organic molecules to CO2 and water under solar irradiation

Methodology Applied

Scientific EffectPhotocatalysis: Photo-oxidation

Implementation Method 3

the sol gel method is quite straightforward and can be easily performed on a wide variety of substrates via spin- or dip-coating a liquid solution containing TiO2 precursor molecules which are subsequently crystallized after an additional heat treatment step

Methodology Applied

Scientific EffectSol-gel process: Sol

Data Source

PatentUS11859105B2Self-cleaning coating

Publication Date: 2024.01.02 UNIVERSITEIT ANTWERPEN

AI summary

A method for forming a self-cleaning coating, comprises providing a first dispersion comprising plasmonic nanoparticles by suspending plasmonic nanoparticles in an organic medium and providing a second dispersion comprising a precursor of a photocatalytic matrix in an organic medium. The method further comprises forming a mixture of the first and second dispersion and coating the mixture on a surface. The method also comprises calcining the coated mixture.