Paper-TiO2composite: An effective photocatalyst for 2-propanol degradation in gas phase

Two simple routes for the synthesis of a paper-TiO2composite were tuned up and the efficiency of the resulting paper-TiO2photocatalyst was investigated in the 2-propanol oxidation in gas phase. The first route involved the in-situ generation over the sheet of paper of a TiO2layer starting from a solution of Ti(OBu)4in tert-butanol/acetic acid, followed by hydrothermal treatment at 120 °C for 3 h. The sample was labelled as paper-TiO2(H). The second approach was based on the adsorption on the paper of a ready-made suspension of titania nanoparticles (TiO2sol), generated in autoclave at 140 °C and stable in acid medium at pH < 3. The sample was labelled as paper-TiO2(S). Evidence of the generation of crystalline TiO2was confirmed by Raman spectroscopy and the morphology of the TiO2layer was analyzed by FE-SEM microscopy. The optical properties of the two paper-TiO2samples and the surface and bulk chemical compositions were studied by UV-vis, XPS spectroscopies and TGA analysis as well. The surface properties of the two paper-TiO2composites in term of wettability were also investigated through water contact angle measurements. The photocatalytic oxidation of 2-propanol in gas phase, under simulated sunlight irradiation in presence of the two paper-TiO2samples was studied at room temperature and compared with a commercial sample, TiO2P25 (Evonik). Both functionalization approaches led to a photoactive paper capable of the complete decomposition of 2-propanol in CO2and H2O within acceptable timescale. The photocatalytic performances of both paper-TiO2composites compare favorably with TiO2P25.