TiO2 Composite Particles with Silver Nanoparticles for Visible Light Photocatalysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for coating ceramic objects with titanium dioxide (TiO2) face issues such as health hazards from nanometric particles, low and non-reproducible catalytic effects, unstable adhesion, and ineffectiveness under normal LED lighting, which limits their photocatalytic and antibacterial properties.

Innovation Solution

Composite particles comprising microparticles of TiO2 with silver-based nanoparticles bound to their surface, produced through a process involving silver ion binding, heating, and drying, enhance photocatalytic and antibacterial activities, including under visible light conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If nanometric particles of TiO2 are used for coating, then photocatalytic properties and ease of cleaning are improved, but health safety deteriorates due to harmful effects of nanometric particles

Engineering Contradiction:
Improvephotocatalytic propertiesVSAvoidhealth safety
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the size parameter of TiO2 particles from nanometric to micrometric dimensions, thereby eliminating health hazards associated with nanoparticle exposure while preserving photocatalytic functionality. The micrometric size range (0.63-2.5 μm) is specifically selected to avoid inhalation risks while maintaining effective surface area for catalytic reactions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates composite particles by combining micrometric TiO2 particles with silver-based nanoparticles on their surface. This composite structure allows the micrometric TiO2 core to provide safety by avoiding nanoparticle exposure, while the silver-based nanoparticle coating enhances photocatalytic activity and provides additional antibacterial properties.

Inventive Principle:
Principle #40Composite materials

2Reliability

If TiO2 is used for coating ceramic objects, then photocatalytic efficiency is improved, but adhesion stability deteriorates over time

Engineering Contradiction:
Improvephotocatalytic efficiencyVSAvoidadhesion stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent employs composite particles consisting of micrometric TiO2 core particles with silver-based nanoparticle shells or surface coatings. This composite structure improves adhesion stability because the silver-based material forms a strong bonding interface with the ceramic substrate, while the micrometric TiO2 core maintains photocatalytic efficiency. The composite nature allows both materials to contribute their advantageous properties.

Inventive Principle:
Principle #40Composite materials

3Reliability

If TiO2 coating is applied to enable photocatalytic activity, then degradation of pollutants is improved under UV light, but effectiveness deteriorates under normal LED lighting conditions

Engineering Contradiction:
Improvepollutant degradationVSAvoidlight condition adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates composite particles with TiO2 and silver-based materials that work synergistically to extend photocatalytic activity from UV-only to visible light range. The silver-based nanoparticles absorb visible light and transfer energy to TiO2, enabling photocatalytic reactions under LED lighting conditions while maintaining effectiveness under UV illumination.

Inventive Principle:
Principle #40Composite materials

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 composite particles demonstrate significantly improved photocatalytic and antibacterial performance, including effective degradation of pollutants and self-cleaning capabilities under various light conditions, with enhanced stability and safety compared to traditional methods.

Implementation Method 1

composite particles comprising (in particular, consisting of) a microparticle of TiO 2 and a plurality of silver-based nanoparticles supported by the microparticle of TiO 2

Methodology Applied
Scientific EffectPhotocatalysis: Photo-oxidation

Implementation Method 2

The tiles treated with TiO 2 are therefore not able to act in the absence of light and are relatively ineffective also when installed in closed environments lit by normal LED lights

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

a drying step, during which the intermediate mixture is dried

Methodology Applied
Scientific EffectThermal drying: Heating

Implementation Method 4

a loading step, during which silver-based nanoparticles are obtained bound to outer surfaces of microparticles of TiO 2

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3277634B1Photocatalytic particles and process for the production thereof
Publication Date: 2020.02.05 GRANITIFIANDRE SPA
  • EP3277634B1 patent drawingFigure 1

AI summary

Method for the production of a treated article having photocatalytic activity; the method comprises an application step, during which composite particles are applied on a surface of a base product comprising ceramic; each composite particle comprises a respective microparticle of TiO2 and a plurality of respective silver-based nanoparticles supported by the relative microparticle of TiO2; the silver-based nanoparticles are 3% to 12% by weight with respect to the overall weight of the microparticles of TiO2 and of the silver-based nanoparticles; the treated article shows surprisingly high photocatalytic properties even if irradiated only in the visible light range.