Chemical binding of pyridine on TiO 2 nanocrystalline film and its photoelectrochemical properties

Aiming to bind molecules without O-containing groups such as the–OH or–COOH functional groups, a new two-step method involving thermal activation and followed by an in situ chemical reaction was suggested, and the binding of the pyridine molecule on TiO 2 nanocrystalline films was realized. UV-Vis, FTIR, and XPS characterizations revealed that pyridine molecules are chemically linked to the TiO 2 surface by forming Ti-pyridine bonds. Mott-Schottky measurements indicated that the binding of pyridine results in a positive shift of the flat band potential for TiO 2 nanocrystalline film, which is attributed to the alternating surface dipole moment of TiO 2 nanocrystals upon pyridine binding. Electrochemical and photoelectrochemical investigations indicated that the binding of pyridine on TiO 2 nanocrystalline film has high electrochemical and photoelectrochemical stability.