Synthesis of multi-walled carbon nanotubes/β-FeOOH nanocomposites with high adsorption capacity

A hybrid nanostructure of multi-walled carbon nanotubes (CNTs) and β-ferric oxyhydroxide (β-FeOOH) nanoparticles is synthesized by ultrasonic-assisted in situ hydrolysis of the precursor ferric chloride and CNTs. Characterization by X-ray diffraction, scanning electron microscopy , and transmission electron microscopy establishes the nanohybrid structure of the synthesized sample. The results revealed that the surface of CNTs was uniformly assembled by numerous β-FeOOH nanoparticles and had an average diameter of 3 nm. The formation route of anchoring β-FeOOH nanoparticles onto CNTs was proposed as the intercalation and adsorption of iron ions onto the wall of CNTs, followed by the nucleation and growth of β-FeOOH nanoparticles. The values of remanent magnetization (Mr) and coercivity (Hc) of the as-synthesized CNTs/β-FeOOH nanocomposites were 0.1131 emu g, and 490.824 Oe, respectively. Furthermore, CNTs/β-FeOOH nanocomposites showed a very high adsorption capacity of Congo red and thus these nanocomposites can be used as good adsorbents and can be used for the removal of the dye of Congo red from the waste water system.