Low-temperature hydrothermal synthesis and functionalization of multiwalled carbon nanotubes

Multiwalled carbon nanotubes (MWCNTs) have been synthesized by facile hydrothermal synthesis technique followed by carboxylic addent functionalization. Crystallographic, topographic, and morphological analyses of pristine and functionalized MWCNTs have been studied using powder X-ray diffraction, electron microscopy, and atomic force microscope, respectively. Fourier transform infrared spectroscopy, UV–Vis absorption spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and Raman spectroscopic studies have been performed for the confirmation of functionalization. Optical, quantitative, and qualitative analysis of the synthesized pristine and functionalized MWCNTs have been performed using energy-resolved and time-resolved photoluminescence and energy-dispersive X-ray spectroscopic studies. Spectroscopic studies confirm the formation of good-quality pristine and functionalized MWCNTs with carboxylic group addent. Electron micrographs reveal the formation of fragmented functionalized MWCNTs with high aspect ratio, whereas diffraction patterns show good crystallinity of synthesized nanostructures. Structural analyses of synthesized and functionalized MWCNTs have been studied using Brunauer–Emmett–Teller surface area analysis and Barrett–Joyner–Halenda pore size and volume analysis technique.