Gas-phase photocatalytic decontamination using polymer supported TiO2

An alternative method to the conventional sol–gel process is proposed to incorporate P-25 TiO2 (Degussa) onto polydimethylsiloxane (PDMS) and orthophthalic polyester (OP) polymers. These TiO2-incorporated films were characterized using SEM–EDS and showed a homogenous distribution of TiO2. The catalytic activity of the films was tested in aqueous phase under black light (365 nm) illumination, using solutions containing dichloroacetic acid, salicylic acid and phenol. OP/TiO2 films presented the best performance, showing no loss of catalytic activity after reuse. Further tests were performed using this film in the form of fixed bed catalyst coated onto the internal walls of a plug-flow concentric gas-phase reactor (767 mL) provided with a black light lamp (365 nm) and an internal area of ∼900 cm2. Ethanol vapor was used as the model compound at 0.05 or 0.02 L min−1 mutually with humid synthetic air at 0.15 or 0.18 L min−1, totaling a 0.2 L min−1 flow rate. A continuous monitoring of the photoreactor outlet using GC–MS showed total mineralization of the model compound within 25 min at a concentration of 126 ppmv. The polymer substrate showed to be resistant to degradation and is a promising material for the decontamination of confined atmospheres.