Catalytic Coatings

Catalytic Coatings

Catalytic coatings play a crucial role in various fields of science and technology by facilitating and controlling chemical reactions. These coatings are made from materials that act as catalysts, accelerating the transformation of substances without being consumed in the process. From air purification to energy production, catalytic coatings offer a wide range of applications and help to develop innovative solutions for technological challenges. Examples of catalytic coatings include platinum on carbon supports for thermocatalytic reactions, zeolite-based coatings for chemisorptive processes, silver-based coatings for electrocatalytic applications, and titanium dioxide-based coatings for photocatalytic transformations.

A major focus of our extensive and long-standing research is the development and application of photocatalytically active coatings.

Photocatalytically active Coatings

Photocatalysis is the transformation of chemical substances under the influence of light. The photocatalyst absorbs light energy and transfers it to a reactive compound, initiating a chemical reaction. Among photocatalysts, the semiconductor titanium dioxide (TiO2) is particularly favored due to its low cost, low toxicity, and strong oxidative properties. Crystalline TiO2, preferably in the anatase form, can nearly completely oxidize most organic substances when irradiated with light < 380 nm. This irradiation generates highly reactive radicals capable of breaking down molecules and organic substances. In addition to radical formation, irradiation leads to superhydrophilicity and a reduction in the water contact angle. When in contact with water (e.g., rain or dew), a thin water film forms on the surface, effectively removing contaminants (easy-to-clean effect). These properties make photocatalytic coatings suitable for a wide range of applications.

Practical applications for photocatalytically active coatings:

• anti-contamination (“easy-to-clean,” self-cleaning surfaces)
• air purification (odor removal, breakdown of VOCs, reduction of NOx)
• water purification (removal of hazardous and persistent biological substances, sterilization)
• antimicrobial activity (prevention of microbial adhesion and biofilm formation)

Using the sol-gel process, various surfaces can be easily and cost-effectively equipped with thin, transparent TiO2 layers. The aim is to impart self-cleaning properties to these surfaces, purify air and water, or eliminate bacteria, algae, and fungi through their antimicrobial action. The versatility of the sol-gel process allows for optimal adaptation to substrate geometries and materials. Unlike antibiotics, no resistance can develop in germs and bacteria during photocatalysis. Additionally, the photocatalytically active coating does not wear out, and no additional chemical substances are required. Once UV light hits the coating, photocatalysis is activated. This makes photocatalysis particularly eco-friendly and sustainable.

We are here to help

We would be pleased to collaborate with you on an R&D project or as a service to develop a coating solution and/or determine the photocatalytic activity for your specific application. We will work with you to develop realistic stress scenarios to quantify the long-term stability of the photocatalytic properties.

  • development and production of photocatalytically active coatings (sol-gel process)
  • Pilot-scale coating trials and production on rigid and flexible substrates
  • Characterization of photocatalytically active surfaces regarding their activity (e.g., assessment of antimicrobial efficacy, dye degradation – e.g., methylene blue according to DIN 52980/ISO 10678)

ANSPRECHPARTNER:
Dr. Helfried Haufe
Fachsektion Dresden – “Funktionelle Schichten”
Tel.: 0351 / 2695 344
E-Mail: dresden@gmbu.de

© Gesellschaft zur Förderung von Medizin-, Bio- und Umwelttechnologien e.V.