Reversible Redox Processes of Poly(anilines) in Layered Semiconductor Niobate Films under Alternate UV-Vis Light Illumination

详细信息    查看全文

• 作者：Yoshihisa Inui ; Tatsuto Yui ; Toshio Itoh ; Kimitaka Higuchi ; Takahiro Seki ; Katsuhiko Takagi
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：October 25, 2007
• 年：2007
• 卷：111
• 期：42
• 页码：12162 - 12169
• 全文大小：224K
• 年卷期：v.111,no.42(October 25, 2007)
• ISSN：1520-5207

文摘

The synthesis of polyaniline (PANI) with semiconducting layered niobate (NbO) to form PANI/NbO hybridmaterials and their reversible color change under a unique redox process under the influence of UV and/orvisible light have been investigated. The in-situ polymerization of anilinium chlorides (ANI) packed in aregular orientation in a bilayer structure within the NbO interlayers led to PANI/NbO hybrid powders byheat treatment using (NH₄)₂S₂O₈ as the catalyst. The resulting PANI of these hybrids showed the characteristicsof a fully oxidized quinoid form, i.e., pernigranine (PG). The PANI/NbO suspension in H₂O was cast on aglass substrate to form a PANI/NbO film after evaporation of the water with a good parallel orientation ofthe NbO layers against the glass substrate. Upon UV light irradiation in the presence of a reductant such asMeOH, the violet-colored PANI (PG) polymers within the NbO interlayers were reduced by the NbO-inducedphotocatalytic reactions and led to a colorless PANI, i.e., leucoemeraldine (LE). Moreover, the resultingcolorless PANI/NbO films reverted back to a blue-colored PANI, i.e., emeraldine (EM), due to oxidation bythe surrounding O₂ gas. The PANI/NbO hybrid films were able to retain repetitive and reversible photoinducedpatterning for over 50 cycles under such alternate UV and visible light irradiation.