Preparation of conductive polypyrrole/TiO2 nanocomposite via surface molecular imprinting technique and its photocatalytic activity under simulated solar light irradiation

Conductive polypyrrole/TiO2 nanocomposites were successfully prepared by surface molecular imprinting technique (MIP-PPy/TiO2) using methyl orange as template molecule. The samples were characterized by means of SEM, XRD, BET and UV–vis diffuse reflectance spectroscopy. Compared with conductive polypyrrole/TiO2 nanocomposites which were prepared by in situ method (Control-PPy/TiO2), the absorption edge of MIP-PPy/TiO2 red-shifts 10 nm, indicating that the band gap energy of MIP-PPy/TiO2 is narrower than Control-PPy/TiO2. Moreover, MIP-PPy/TiO2 nanocomposites show higher adsorption capacity and selectivity for template molecule than Control-PPy/TiO2 nanocomposites, and the photocatalytic activity of MIP-PPy/TiO2 is two times of Control-PPy/TiO2, which is attributed to the introduction of the imprinted cavities on the surface of MIP-PPy/TiO2 nanocomposites. Therefore, surface molecular imprinting method may be considered as a novel technology for the preparation of PPy/TiO2.