Zinc Oxide Decorated Multiwalled Carbon Nanotubes: Their Bolometric Properties

We report the synthesis of MWNTs/ZnO hybrid nanostructures. A simple, affordable, chemical procedure to functionalize MWNT with ZnO nanoparticles was performed. A significant portion of the surface of MWNTs is covered with ZnO nanoparticles, such particles form highly porous spherical nodules of 50-150 nm in diameter, sizes that are in values one order of magnitude larger than similar ZnO nanonodules reported in the literature. Hence, in the self-assembled nanocomposite the ZnO exhibits a large surface to volume ratio, which is a very advantageous property for potential catalytic applications. The resultant MWNTs/ZnO nanocomposites were characterized by X-ray diffraction, scanning and high-resolution transmission electron microscopy, and UV-Vis and Raman spectroscopies. The temperature coefficient of resistance (TCR) of the nanocomposites was measured and reported. The average TCR value goes from -5.6%/K, and up to -18%/K, on temperature change intervals from 10 K to 1 K, respectively. Based on TCR results, the nanocomposite MWNTs/ZnO prepared in this work is a promising material with potential application as a bolometric sensor.