Nonlinear optical modification of single-walled carbon nanotube by decorating with metal and metal-free porphyrins

Abstract

Two porphyrins functionalized single-walled carbon nanotube nanohybrids (SWCNT-TPP and SWCNT-TPPZn) have been prepared following the free radical addition reaction and subsequent nucleophilic substitution. The results of microscopic structure and morphology analysis, including Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis, confirmed the successful fabrication of SWCNT-TPP and SWCNT-TPPZn nanohybrids. UV–vis absorption, Raman and fluorescence emission studies indicate considerable π-π interactions and effective charge transfer from the porphyrin moieties to the SWCNT. Z-scan investigations show that both nanohybrids exhibit improved nonlinear optical performances in the ns and fs regimes compared to those of individual SWCNT and porphyrins; this is proposed to result from a positive synergistic effect between SWCNT and porphyrins. Due to more effective charge transfer effect, SWCNT-TPP nanohybrid exhibit the best NLO performance at 532 and 800 nm.