Chemical binding of pyridine on TiO2 nanocrystalline film and its photoelectrochemical properties

Abstract

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 TiO2 nanocrystalline films was realized. UV-Vis, FTIR, and XPS characterizations revealed that pyridine molecules are chemically linked to the TiO2 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 TiO2 nanocrystalline film, which is attributed to the alternating surface dipole moment of TiO2 nanocrystals upon pyridine binding. Electrochemical and photoelectrochemical investigations indicated that the binding of pyridine on TiO2 nanocrystalline film has high electrochemical and photoelectrochemical stability.