Photocatalytic Filtration
Photocatalytic filtration activated by titanium dioxide offers a simple, natural method to reverse contamination, maintain surface cleanliness, and purify the air. This powerful technology is designed to abate odors, neutralize microbes, and break down volatile organic compounds (VOCs) and chemically active agents.
what is photocatalytic filtration
a natural process
Chlorophyllian photosynthesis is the process through which plants synthesize nutrients from water, mineral salts, and atmospheric carbon dioxide, while releasing oxygen.
This transformation requires two elements: chlorophyll, a catalyst, and light, which provides the energy to activate chlorophyll (the term photosynthesis comes from the Greek word "photo," meaning "light").
During photosynthesis, sunlight energizes chlorophyll to create carbon (C) from CO2, hydrogen (H) from H2O, oxygen (O) from the air's O2, and nitrogen (N) from fertilizer, resulting in the formation of CHON.
As in chlorophyll photosynthesis, UV light (natural or artificial) activates titanium dioxide. This catalyst breaks down the organic substances absorbed by its surface into their constituent elements: water vapor, carbon dioxide and minerals.
In photocatalytic filtration, titanium dioxide (TiO2) replaces the function of chlorophyll in photosynthesis.
Filtration Performance
by Category
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MECHANICAL FILTER(HEPA) |
ACTIVATED CARBON(STANDARD) |
PHOTOCATALYTIC FILTER(+UVC) |
|---|---|---|---|
DUST AND PM |
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UNPLEASANT ODORS VOCs |
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VIRUSES AND BACTERIA |
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CHEMICAL SUBSTANCES |
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LIFESPAN AND REGENERATION |
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FINAL EFFECT |
ENTRAPMENT |
ADSORPTION |
REMOVAL |
Benefits of photocatalytic filtration
High performance, sustainability, and value.
Photocatalytic filtration is an advanced solution that redefines purity standards. A single device provides effective bactericidal sanitization, odor abatement, and purification from Volatile Organic Compounds (VOCs). Unlike simple filtration, this technology operates through the molecular destruction of pollutants.
High Efficiency.
The system can neutralize and decompose hazardous particles down to 0.001 microns. For perspective, medical-grade HEPA filters are rated to trap particles from 0.3 microns. This superior performance guarantees the elimination of even the most microscopic contaminants.
Sustainability
The process operates with high selectivity, focusing exclusively on attacking VOCs, bacteria, and odor molecules, without interacting with or altering other gases present in the air. It is an eco-friendly method, as it does not use hazardous chemicals and the purification process produces no harmful by-products.
Durability and user-friendly operation.
Photocatalysis not only purifies the air but also regenerates the filter itself, ensuring a longer lifespan than traditional filters. At the same time, its low pressure drop allows for optimal installation and operation in any type of system.
Photocatalytic filtration applications
A wide range of applications
High-efficiency photocatalytic filtration is the perfect choice for any environment where neutralizing VOCs and ensuring total sanitization are top priorities.
The extraordinary purifying capabilities of titanium dioxide are already a well-established reality in large-scale and high-visibility applications, such as TX Active ® construction materials by Heidelberg Materials, 'smog-eating' asphalts, and innovative self-cleaning glass technologies (such as Saint-Gobain Bioclean, Pilkington Activ, and Sunclean).
FAQ's
Everything about photocatalytic filtration
What is photocatalytic filtration and how does it work?
Photocatalytic filtration is a natural process inspired by chlorophyll photosynthesis. Just like chlorophyll in plants, the titanium dioxide (TiO₂) – deposited on the filter – is activated by UV light (either natural or artificial). Once activated, the TiO₂ generates oxidizing radicals that break down the organic substances absorbed on the filter’s surface into their basic elements: water vapor, CO₂, and inert minerals.
Unlike traditional mechanical or carbon filters, photocatalysis doesn't just trap or absorb pollutants—it destroys them at a molecular level.
Which light source is needed to activate TiO₂?
Titanium dioxide is activated by ultraviolet (UV) rays, which can be derived from:
- Natural – sunlight (in outdoor applications or bright environments)
- Artificial – UVA or UVC lamps integrated into the filtration system
In high-efficiency indoor applications, such as air sanitization, UVC lamps are combined with photocatalytic filters to maximize the reduction of pathogens and VOCs.
Unlike traditional mechanical or carbon filters, photocatalysis doesn't just trap or absorb pollutants—it destroys them at a molecular level.
Down to what particle size is photocatalysis effective?
Photocatalytic systems can neutralize particles and molecules down to 0.001 microns. By contrast, HEPA filters (the medical-grade benchmark) capture particles as small as 0.3 microns. This makes photocatalysis effective at a scale 300 times finer than HEPA standards.
Does photocatalysis produce harmful by-products?
No. The process is eco-friendly: it does not use additional chemical agents, and the final decomposition products are exclusively water vapor, CO₂, and inert minerals, which are completely harmless. Photocatalysis operates with high selectivity, attacking only VOCs, bacteria, and odor molecules without altering other gases present in the air.
What are the primary applications of photocatalytic filtration?
Photocatalysis is used wherever air quality control is required. Depurex’s primary application sectors include:
- Odor abatement – industrial plants, livestock farms, composting facilities
- Atmospheric emissions – VOC control and reduction in production processes
- Indoor Air Quality (IAQ) – sanitization of healthcare facilities, offices, and public areas
- Fruit and Vegetable Preservation – ethylene abatement to extend the shelf life of fresh produce
How does photocatalytic odor abatement work?
The molecules responsible for unpleasant odors are Volatile Organic Compounds (VOCs). Photocatalysis acts at a molecular level: the radicals generated by TiO₂ break the chemical bonds of these molecules, degrading them completely into CO₂ and H₂O. This process eliminates the odor source at its root, rather than merely masking it or temporarily absorbing it.
Does photocatalysis also eliminate viruses and bacteria?
Yes. Photocatalysis, especially when combined with UVC lamps, ensures high bactericidal and virucidal efficacy. The oxidizing radicals generated by TiO₂ attack and destroy the cell membranes of microorganisms, rendering them inactive. This combination is particularly recommended for indoor air sanitization in sensitive environments (hospitals, clinics, schools).
How is it used for fruit and vegetable preservation?
Fresh produce emits ethylene, a gas that accelerates ripening and spoilage. Photocatalysis continuously degrades the ethylene molecules present in cold storage rooms or warehouse areas, slowing down the ripening process and significantly extending shelf life without the use of chemical additives or post-harvest treatments. Industry studies demonstrate that rigorous ethylene control can extend the shelf life of fruit and vegetable products from a few days to several weeks, depending on the specific variety.
Are Depurex ethylene abatement systems compatible with organic farming?
Yes, our photocatalytic filtration systems are ideal for the organic sector. They do not use synthetic chemicals and leave no residues on the products, acting exclusively through a natural physical-chemical process activated by light.
What is the lifespan of a Depurex photocatalytic filter?
Photocatalytic filters have a longer lifespan than traditional filters, as the photocatalytic process degrades the organic substances accumulated on the filter, continuously regenerating it. The service life varies based on the pollutant load and the specific application.
Are Depurex filters compatible with existing systems?
Yes. The low pressure drop of Depurex photocatalytic filters allows for installation in any type of ventilation or air treatment system, without requiring significant structural modifications. Depurex also designs and produces custom-made filters, adaptable to any dimensional or application requirement, even in limited series.
What is meant by 'photocatalytic fabrics' and when are they used?
Photocatalytic fabrics (or sheets) are flexible filtering elements impregnated with titanium dioxide, used as an extended photocatalytic surface. They are employed in applications where a large treatment area is required, such as ventilation ducts, greenhouses, or air treatment systems with low pressure drop. They can be easily cut and adapted to the required dimensions.
Are photocatalytic filters sensitive to humidity?
Not at all. On the contrary, they perform better with humidity, whereas other filtration systems are negatively affected by it.
Can Depurex develop custom filters for specific requirements?
Absolutely. Depurex specializes in the design and production of custom-made filters, including for non-standard applications and in limited batches. If you have a specific filtration requirement that is not met by our catalog products, the Depurex team will analyze your case and develop the most suitable solution. Contact us to request a free technical consultation.
What is the difference between a photocatalytic filter and a HEPA filter?
The main difference lies in how they handle pollutants: the HEPA filter traps them, while the photocatalytic filter destroys them.
The HEPA filter has a mechanical action; it works like an ultra-high-density sieve. It is excellent for trapping physical particles such as dust, pollen, and micro-particulate matter (PM10, PM2.5). However, it is not effective against gases, odors, and VOCs (Volatile Organic Compounds). Furthermore, trapped microorganisms remain alive on the filter surface, requiring frequent replacements to prevent biological risks.
The photocatalytic filter, on the other hand, utilizes the principle of photocatalysis to trigger a natural oxidation process. Instead of simply trapping pollutants, it decomposes them at a molecular level, transforming viruses, bacteria, molds, and harmful gases into harmless substances such as water vapor and CO2
How does it differ from activated carbon filters?
Activated carbon filters temporarily adsorb odor molecules and some VOCs, but they become saturated over time: once exhausted, they can release the accumulated substances back into the atmosphere (a phenomenon known as desorption). In contrast, the photocatalytic filter permanently mineralizes contaminants instead of accumulating them, maintaining performance over time and eliminating the risk of secondary release.
The final effect is the key difference: capture (HEPA), adsorption (activated carbon), elimination (photocatalysis).
Can I integrate photocatalytic filtration with existing systems?
Yes, photocatalysis is extremely versatile: it can operate independently or be integrated as a technological upgrade for existing systems. Used as a final stage, it acts where mechanical filters and activated carbon reach their limits, ensuring the definitive molecular decomposition of pollutants and a superior air quality that remains constant over time.
Still have doubts about how to apply photocatalytic filtration to your system?
Every environment has unique purification needs. Our technicians are at your disposal to analyze your specific case and design the most effective filtration solution.