Study of MWCNT Dispersion Effect in TiO2-MWCNT Composites for Gas-Phase Propene Photooxidation

Abstract

We have performed the synthesis of TiO2-MWCNT composites focusing on the distribution of the photoactive phase on the carbon active sites existing in the MWCNTs, and its effect on the properties of the composites for the abatement of propene. We have used different approaches for the dispersion of MWCNTs during the synthesis; 1) an ultrasound bath for 5 minutes, 2) an ultrasound bath for 60 minutes, and 3) an ultrasound probe for 5 min. We observed that the incorporation of MWCNTs in the TiO2 synthesis improves the catalytic activity in the photooxidation of propene, but the best results are obtained for ultrasound probe treatment. A good dispersion of the MWCNT and an increase in the active surface area or surface oxygen functionalities of the MWCNTs are key factors to achieve improved photocatalytic activity for total propene oxidation, thus benefitting from the synergy between TiO2 and MWCNT.