Nanocomposite of Polyaniline and a Layered Niobate Acid Host: Synthesis, Electrochemical Studies, and Photocatalytic Properties

摘要

The synthesis of polyaniline (PANI) with H4Nb6O_(17) (HNbO) to form PANI/HNbO lamellar nanocomposite by in situ polymerization using aniline (ANI) intercalation compound ANI/HNbO as the intermediate has been investigated. The properties of the samples were characterized by means of XRD, SEM, TEM, FT-IR, UV-vis spectroscopy, and TG-DTA. The in situ polymerization of ANI packed in a regular orientation in a mono- and bilayers (i.e., pseudo-bilayers) structure within the HNbO interlayers led to PANI/HNbO nanocomposite powder using (NH4)2S2O8 as the catalyst with PANI monolayer packing orientation within the HNbO interlayers. PANI/HNbO nanocomposite showed improved thermal stability compared with original PANI by TG analysis. The PANI/HNbO nanocomposite was studied by cyclic voltammetry (CV), which indicated the good redox activity and electrochemical-cycling stability in acidic solution. The interaction between PANI and nanosheets greatly affected the electrochemical behavior of PANI/HNbO nanocomposite. Two couples of redox peaks corresponded to two oxidation process of PANI in acid conditions. The PANI/HNbO nanocomposite exhibited much higher photocatalytic activities for the degradation of methylene blue (MB) in aqueous solution under visible light irradiation than HNbO itself.