Copper-Titanium Tungsten Oxide Photocatalyst Stability
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Solution Overview
Problem
Existing photocatalytic materials, particularly those containing copper, suffer from instability and reduced efficacy when exposed to heat or ultraviolet radiation, and lack sufficient activity under visible light, making them unsuitable for long-term applications in indoor settings where light sources primarily emit visible light.
Innovation Solution
A titanium oxide-tungsten oxide composite photocatalytic fine particle dispersion is developed, where copper is incorporated into the titanium oxide particles in a solid solution state, enhancing stability and durability, and mixed with tungsten oxide particles to achieve high photocatalytic activity under visible light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper-containing photocatalytic materials are used to enhance visible light activity and antibacterial properties, then photocatalytic performance is improved, but stability and durability under heat and ultraviolet radiation deteriorate
Solution Approach 1:
The invention creates a composite structure where copper atoms are incorporated into the titanium oxide crystal lattice, forming a stable composite material. This composite approach allows the copper to provide visible light activity while the titanium oxide matrix maintains structural stability under UV and heat exposure, preventing copper aggregation and coordination state changes.
Solution Approach 2:
The copper is not uniformly distributed but specifically incorporated at particular sites within the titanium oxide crystal structure. This local incorporation at specific lattice positions allows copper to exert its photocatalytic effect while being protected by the stable crystal environment, preventing unwanted chemical changes under various conditions.
2Productivity
If copper is added to enhance visible light sensitization and antibacterial activity, then initial efficacy is improved, but durability under environmental exposure deteriorates
Solution Approach 1:
The copper atoms are pre-incorporated into the titanium oxide crystal lattice during the synthesis process, creating a stable structure before the material is deployed. This preliminary incorporation ensures that the copper is properly positioned and stabilized from the outset, preventing later degradation when exposed to environmental conditions like moisture, heat, and light.
3Power
If conventional copper-containing catalysts are used, then initial catalytic activity is high, but long-term stability under environmental conditions deteriorates
Solution Approach 1:
The invention changes the fundamental parameter of copper's chemical environment by incorporating it into the titanium oxide crystal lattice rather than using conventional supported copper oxide. This parameter change in the coordination environment transforms copper from a unstable, easily-altered state to a stable, lattice-protected state that maintains catalytic activity while resisting environmental degradation.
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 dispersion maintains or improves photocatalytic performance while reducing the amount of rare metal tungsten used, ensuring stability and durability under visible light exposure, and exhibits high antibacterial activity.
Implementation Method 1
the titanium oxide-tungsten oxide composite photocatalytic fine particles... which manifests a photocatalytic activity even on exposure only to visible light (400 to 800 nm)
Implementation Method 2
photocatalytic action when irradiated with light that includes ultraviolet light at wavelengths of up to 400 nm... holes and electrons that have been generated by excitation with UV light... and have diffused to a surface carry out redox reaction together with molecules adsorbed to that surface
Implementation Method 3
holes and electrons that have been generated by excitation with UV light at up to 400 nm
Implementation Method 4
tungsten oxide-titanium oxide composite photocatalytic fine particles... which manifests a photocatalytic activity even on exposure only to visible light (400 to 800 nm)
Data Source
AI summary
The present invention relates to a dispersion liquid of titanium oxide-tungsten oxide composite photocatalytic fine particles that is characterized by having two types of photocatalytic fine particles dispersed in an aqueous dispersion medium, the fine particles including i) fine particles of titanium oxide that contain a peroxotitanium component and a copper component and ii) fine particles of tungsten oxide. The present invention can provide a dispersion liquid and the like that can be used to conveniently manufacture a photocatalytic thin film that demonstrates photocatalytic activity even within visible light (400-800 nm) only, exhibits high antibacterial performance, is highly durable, and wherein the state of copper coordination is stable against exposure to heat and ultraviolet rays and is not easily modified. The dispersion liquid is a dispersion liquid of titanium oxide-tungsten oxide composite photocatalytic fine particles that contains copper-containing titanium oxide fine particles.