The main objective of this project was to develop the next generation air purifiers, in which PCO technology would allow elimination of a variety of hazardous indoor air pollutants, and bad odour caused by such pollutants, when illuminated by low-power light sources on-the-fly. To achieve our goal, we worked on the development of more ordered and interconnected photocatalytic materials, and therefore, we synthesized the photocatalytic element in-house and operate them under visible light. The main outcomes of this study were:
• A new chemistry laboratory was set up at Arçelik Central R&D facilities for the synthesis of photocatalytic materials and also for the performance tests of both benchmarks and home-made air purification systems.
• We developed mesoporous pure anatase TiO2-based materials with high surface area and large pore volume in powder form.
• Sol of photocatalytic materials could be successfully coated on quartz surfaces.
• The synthesis materials were able to absorb visible light between 400 and 800 nm.
• In plate-like reactor design, uniform air flow distribution and effective illumination could be sustained which led to effective use of catalyst surfaces during PCO reaction.
• Visible light sources (0.1-1.4 W/m2) had very low irradiance power compared to UV light sources (270 W/m2).
• Formaldehyde could be easily degraded to CO2 and H2O on anatase TiO2 surfaces in both experimental studies and theoretical DFT calculations.
• We showed that formaldehyde combustion was more favourable on An(101) TiO2 than An(001).
• Apparent barrier between the reaction steps of cyclic structure of formaldehyde (-CH2-O-) and water adsorption became lower when Fe was doped on TiO2. Moreover, the whole combustion cycle stayed at exothermic region in case of Fe/TiO2 An(001).
• Degradation of aromatic rings (benzene and toluene) was slower than aliphatics (i.e. n-hexane) on anatase TiO2 surfaces.
• Experimentally, benzene degradation was more difficult than toluene on anatase TiO2.
• We proved with DFT studies that both adsorption and the ring opening reactions of benzene on anatase TiO2 surfaces was very difficult. This might be the reason for the slower conversion of benzene than toluene in experimental studies.
• We predicted that although benzene could be adsorbed on the TiO2 anatase surfaces, it was probably very easily desorbed either being benzene molecule or most probably forming phenol.
In this project, we established a collaboration with Dr. Olus Ozbek from Yeditepe University to investigate the formation of intermediate products of PCO reaction, to derive reaction pathways and to calculate the energy required to overcome the activation barriers of rate-determining steps.
Dissemination of the project:
I took part in a twitter chat on 4th of July 2017. The event organized by MSCA Team. I answered the questions of the researchers, who were interested and keen to apply for MSCA-IF grant in the Society & Enterprise panel.
I made a presentation at my former university (Middle East Technical University) to around 60 B.Sc. students. I talked about my career path and experiences gained till now, and explained the scope of my MSCA project and the planned studies for the short- and long- term.
I joined to an interview for the Horizon Magazine and we talked about the effect of air pollution to human health and how we looked at the problem towards bringing a viable solution. The article can be tracked from the link:
https://horizon-magazine.eu/article/artificial-forest-air-and-light-based-chemical-reactions-tackle-indoor-pollution.html(opens in new window)
