(132b) Adsorption of Methylene Blue from Aqueous Solution By Zirconia Nanoparticles on Multiwall Carbon Nanotubes

Synthetic dyes are widely used as coloring agents in textile, paper, leather, gasoline, pharmaceutical, and food industries. These dyes interfere in the processes of aquatic life, preventing the free passage of light and affecting the operation of wastewater treatment plants. The dye degradation products are toxic, carcinogenic and cause an increase in the levels of chemical oxygen demand (COD) and biological oxygen demand (BOD).

In this work, we report the adsorption of methylene blue onto zirconia nanoparticles supported on multiwalled carbon nanotubes (MWCNTs) via a microwave-assisted method. For the synthesis of circonia nanoparticles, zirconium (IV) oxynitrate hydrate was used as a metal source. Dioctyl sulfosuccinate sodium salt and sodium borohydride were used as surfactant and reducing agent, respectively. (+)-α-Pinene and ferrocene were used as a carbon source and catalyst respectively for the synthesis of MWCNTs.

The resulting composites were characterized by HRTEM, XRD, TGA and Raman spectroscopy. This method enabled the growth of a homogeneous coating around the multiwall carbon nanotubes. The adsorption studies were carried out using UV-Vis spectroscopy. The produced nanocomposites showed higher dye adsorption capability and removal percentage (77.0 mg/g, 97.0 %) than the functionalized carbon nanotubes (37.1 mg/g, 56.7%). Increasing the temperature increased the adsorption capacity of the composite. The zirconia/multiwalled carbon nanotube composites show great potential to remove methylene blue from contaminated water.