Synthesis of Carbon Nanotubes from Graphite and Investigation of the Catalytic Activity of MWCNTs/Cr₂O₃–NiO with the Removal of Bismark Brown G Dye from Its Aqueous Solution

This work describes the synthesis of carbon nanotubes from graphite by the chemical precipitation method and nanocomposites of multiwall carbon nanotubes (MWCNTs) with co-oxide nanocomposite (MWCNTs)/MO(Cr 2 O 3 –NiO). Those nanocomposites were prepared with the use of a simple evaporation and a drying process. The obtained composites were characterized, by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The activity of the prepared composites was investigated by the follow- ing removal of a Bismarck brown G dye (BBG) from the aqueous solution via photocatalytic reactions. The efficiency of the photocatalytic dye removal over the prepared composites was 91.43% after one hour of reaction under the optimal conditions, which were a mass dosage of 0.03 g, pH = 5, and a temperature of 30 ∘ C.