Cellulose acetate-TiO₂ and activated carbon electrospun composite fibre membranes for toluene removal

The VOCs removal from polluted air has been achieved using several different methods but primarily through the use of adsorbent materials or through degradation with photocatalytic oxidation (PCO). Fibres produced by electrospinning have the possibility to easily incorporate additives into the fibres and onto their surface. This can functionalise them for efficient VOCs removal. Cellulose acetate (CA)-based electrospun fibre membranes have been fabricated and doped with activated charcoal (AC) and titanium dioxide (TiO2), either separately or in combination to investigate their toluene removal capacity of the single additive and the synergic effects of adsorption and PCO. Two different methods of functionalisation of the fibres with AC and TiO2 have been used. These methods are air spraying and electro-spraying. Several configurations of the final membranes have been investigated. SEM images indicate that the additives have been successfully distributed on the fibre surface and they affect their morphology by increasing the overall roughness and the thickness of the final membranes. Adsorption with AC achieved 45.5% removal of toluene with a starting concentration of 22.5 ppm. PCO was probably initiated using a blacklight blue UV lamp with a peak wavelength of 365 nm as formation of formaldehyde was recorded. The findings suggest that PCO is affected by the residence time and UV light intensity.