Facile Synthesis and Enhanced Nonlinear Optical Properties of Porphyrin-Functionalized Multi-Walled Carbon Nanotubes

• Published in: Chemistry : a European journal 2013-10, Vol.19 (42), p.14159-14170
• Main Authors: Wang, Aijian, Fang, Yu, Long, Lingliang, Song, Yinglin, Yu, Wang, Zhao, Wei, Cifuentes, Marie P., Humphrey, Mark G., Zhang, Chi
• Format: Article
• Language: English
• Subjects: Attachment; Chemistry; Composite materials; Covalence; Cycloaddition; Multi wall carbon nanotubes; Nanostructure; Nanotubes; nonlinear optics; Nonlinearity; Optical properties; porphyrinoids; Porphyrins; Spectrum analysis
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201302477

Two multi‐walled carbon nanotube (MWCNT)‐based nanohybrids, MWCNT–ZnTPP and MWCNT–TPP (TPP=5‐[4‐{2‐(4‐formylphenoxy)‐ ethyloxy}phenyl]‐10,15,20‐triphenylporphyrin, ZnTPP=5‐[4‐{(4‐formylphenyl)ethynyl}phenyl]‐10,15,20‐triphenylporphinatozinc(II)), were prepared directly from pristine MWCNTs through 1,3‐dipolar cycloaddition reactions. Covalent attachment of the porphyrins to the surfaces of the MWCNTs was confirmed by Fourier transform infrared spectroscopy, ultraviolet/visible absorption, fluorescence, Raman, and X‐ray photoelectron spectroscopy, elemental analysis, transmission electron microscopy, and thermogravimetric analysis. Attachment of the porphyrin moieties to the surface of the MWCNTs significantly improves the solubility and ease of processing of these MWCNT–porphyrin composite materials. Z‐scan studies reveal that these MWCNT–porphyrin nanohybrids exhibit enhanced nonlinear optical properties under both nanosecond and picosecond laser pulses at λ=532 nm in comparison with free MWCNTs and the free porphyrin chromophores, whereas superior optical limiting performance was displayed by MWCNT–porphyrin composite materials rather than MWCNTs/ZnTPP and MWCNTs/TPP blends, which is consistent with a remarkable accumulation effect as a result of the covalent linkage between the porphyrin and the MWCNTs. Enhanced nonlinear properties: Two porphyrin‐functionalized multi‐walled carbon nanotubes (MWCNTs) were constructed by facile 1,3‐dipolar cycloaddition reactions. Covalent attachment of the porphyrin moieties to the surface of the MWCNTs significantly improves their solubility and processability. The enhanced optical nonlinearities were observed for such porphyrin‐functionalized MWCNT nanohybrids, which can be attributed to the covalent linkage between the porphyrin and the MWCNTs.