Preparation and Optical Limiting Properties of Multiwalled Carbon Nanotubes with π-Conjugated Metal-Free Phthalocyanine Moieties

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• 作者：Nan He ; Yu Chen ; Jinrui Bai ; Jun Wang ; Werner J. Blau ; Jinhui Zhu
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：July 30, 2009
• 年：2009
• 卷：113
• 期：30
• 页码：13029-13035
• 全文大小：390K
• 年卷期：v.113,no.30(July 30, 2009)
• ISSN：1932-7455

文摘

Phthalocyanines (Pcs) usually exhibit stronger optical limiting response that can be used to protect human eyes, optical elements, and sensors from intense laser pulses. New unsymmetrically substituted metal-free phthalocyanine-covalently functionalized multiwalled carbon nanotubes (PcH₂-MWNTs), in which the wt % of MWNTs in the resulting product was found to be 35%, were synthesized. A considerably quenching of the fluorescence intensity was found in the photoluminescence spectrum of PcH₂-MWNTs. This observation suggests a quenching of the singlet excited PcH₂ by the covalently linked MWNTs. This material exhibits strong scattering at higher intensities, which evidently comes from the MWNT counterpart. The nonlinear response of tBu₃NH₂PcH₂ is due to reverse saturable absorption (RSA), while that of PcH₂-MWNTs is due to both RSA and nonlinear scattering, which could be two conflicted mechanisms for optical limiting, giving rise to suppression of the whole nonlinear response of PcH₂-MWNTs.