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

Abstract

The synthesis of p-type polyaniline (PAN) by the in situ polymerization of aniline in the confined interlamellar galleries of an n-type semiconducting layered protonic titanate (LPT) affords an 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 π−π* 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.