Covalent functionalization and characterization of multi-walled carbon nanotubes using 5, 10, 15, 20-tetra(4-aminophenyl)porphyrinatonickel(II)

5,10,15,20-tetra(4-aminophenyl)porphyrinatonickel(II) was covalently connected to multi-walled carbon nanotube (MWCNT) through an amide linkage and characterized by using many spectroscopic techniques. In FT-IR, the carbonyl peak (C = O) of MWCNT-NiTAP is shifted to higher frequency as compared to the reported MWCNT-TAP due to Ni ion substitution. Notable changes in the FT-IR and XP spectra confirms the covalent functionalization of Ni-TAP with MWCNTs. Raman spectra indicate that the ID/IG ratio is less for MWCNT-NiTAP as compared to MWCNT, MWCNT-COOH, MWCNT-ZnTAP and MWCNT-CuTAP which is due to improved electronic properties of MWCNT-NiTAP. TGA plots of MWCNT-NiTAP reveals that similar to 30% weight loss in the temperature range of 150-800 degrees C. Considerable shift in the absorption and emission spectra of the nano hybrid clearly indicate different electronic interaction between porphyrin and MWCNT due to nickel ion substitution. PL spectra of MWCNT-NiTAP exhibited fluorescence quenching of Ni-TAP Soret band by MWCNTs. This quenching is owing to the energy or electron transfer between Ni-TAP and MWCNTs.