Synthesis and Photocatalytic Properties of a Polyaniline-Intercalated Layered Protonic Titanate Nanocomposite with a p-n Heterojunction Structure

The synthesis of p-type polyaniline (PAN) by the ill situ polymerization of aniline in the confined interlamellar galleries of all n-type semiconducting layered protonic titanate (LPT) affords all intercalated PAN/LPT nanocomposite. The in situ polymerization of aniline can be initiated by oxygen in the air. The resulting nanocomposites have been characterized by XRD, FTIR, UV-visible spectroscopy, TG-DTG, SEM, and elemental analysis. The PAN/LPT nanocomposites show significant absorption in the visible region, whereas the pristine LPT absorbs only in the Ultraviolet region. Under visible irradiation, the PAN pi-pi* transition delivers excited electrons into the conduction band of LPT, and the subsequent electron transfer to a substrate electrode contributes to the photocurrent. The PAN/LPT nanocomposites exhibit much higher photocatalytic activities for the degradation of methylene blue in aqueous solution under visible light irradiation than LPT itself.