Investigation of the TiO2/PPV nanocomposite for gas sensing applications

It is well established that the dispersion of nanosized metal particles in a polymer matrix can induce nonlinear optical properties, yet very little i s known about the effect of semiconducting transition metal oxide nanoparti cles on luminescence properties of conjugated polymers. In this paper, we r eport the synthesis of a nanostructured TiO2/poly(p-phenylenevinylene) (PPV ) system and show by diffuse reflectance infrared Fourier transform spectro metry that a stable conjugated nanocomposite is obtained. Investigation of the photoluminescence (PL) properties reveals both a broadening and a blues hift of the emission spectra. Adsorption of oxygen is found to be stronger on the nanocomposite than on PPV and to reversibly quench the PL emission, thus suggesting enhanced gas sensing properties. A tentative mechanism expl aining the role of n-TiO2 is briefly discussed.