Preparation, testing and performance of a TiO2/polyester photocatalyst for the degradation of gaseous methanol

TiO2 modified polyester photocatalysts were prepared by immersion, drying and curing of the polyester in TiO2 containing suspensions under different experimental conditions. The structure of TiO2 layers on the polyester varied according to the time of immersion and type of polyester used. The optical microscopy (OM) and scanning electron microscopy (SEM) show a more uniform distribution of TiO2 on the polyester prepared by sol–gel as compared to the silicone as a binder. Energy diffuse spectroscopy (EDS) and infrared (ATR-FTIR) spectroscopy confirmed that TiO2 bonded to the polyester textile. BET analysis showed that TiO2–SiO2 applied by sol–gel on polyester led to a higher surface area compared to silicon. Photodegradation of gaseous methanol mediated by the TiO2–polyester was followed by gas chromatography (GC) and ATR-FTIR spectroscopy. The TiO2–polyester sample prepared by sol–gel with an immersion time of 11 h exhibited the most favorable photocatalytic performance during methanol degradation in the gas phase. The best performance during methanol photodegradation was observed for the smallest agglomerate TiO2 size. The structure–reactivity relationship for different photocatalysts was systematically explored. Quantitative evaluation of the cluster size, immersion time and catalyst loading provided the evidence for the best performance for methanol degradation by the catalyst prepared at 11 h immersion time. The photocatalytic activity of the TiO2–polyester catalyst was observed to remain stable during methanol over several degradation cycles.