Al2O3/MnO2/CNTs nanocomposite: Synthesis, characterization and phenol adsorption

Abstract

Unique properties of carbon nanotubes (CNTs) and metal oxide nanoparticles can be integrated to produce hybrid materials providing special features for various applications. In this study, wet impregnation technique was employed to impregnate the multi wall carbon nanotubes (MWCNTs) with different amounts of alumina (Al2O3) and manganese dioxide (MnO2). Raw and synthesized nanocomposites were characterized to study the surface texture, thermal stability, porosity, mineralogy and surface functional groups of materials using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), N2 physisorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) and RAMAN spectroscopy. SEM micrographs and XRD diffractograms revealed that the Al2O3 and MnO2 had good dispersion on the MWCNTs surface. Thermal analysis demonstrated that presence of metallic constituents catalyze the oxidation of carbon and decreases the value of initial decomposition temperature of raw MWCNTs. Surface area and porosity were get reduced by impregnating MWCNTs with metals oxides due to coverage of outer surface of substrate with metal oxide nanoparticles. Application of synthesized nanocomposites showed almost 15% higher removal efficiency for removal of phenol from aqueous phases as compared to raw MWCNTs. These results indicate that this nanocomposite can be used for environmental remediation applications.