Poly(3-hexylthiophene)/titanium dioxide nanocomposites prepared by in-situ polymerization: structure, morphology and electrochemical properties

In this work, poly(3-hexylthiophene) (P3HT) nanocomposites with different mass percentages of TiO2 nanoparticles (NPs) (1.0, 2.0 and 5.0% wt.) were prepared by in-situ polymerization to assess the effects of NPs on the physical and chemical properties of the P3HT polymer. Green TiO2 NPs in the anatase crystalline phase were obtained by microwave-assisted synthesis. Transmission electron microscopy images showed the presence of submicron agglomerates of TiO2 NPs inserted in the P3HT matrix. Cyclic voltammograms evidenced a quasi-reversible behavior at a 50 mV s(-1) sweep rate for all samples, with the P3HT-TiO2 nanocomposite exhibiting a higher oxidation potential than P3HT. The nanocomposite containing 2.0% wt. TiO2 exhibited the highest thermal stability and the highest potential for application in photovoltaic devices due to its regiochemistry, which improved the charge transport properties of the P3HT polymer.