In this study, some types of composites consisting of multi-walled carbon nanotubes (MWCNTs) and spinel oxide
(Co, Ni)
3
O
were synthesized by simple evaporation method. These composites were characterized by UV–Vis
diffuse re? ectance spectroscopy, X-rays diffraction(XRD), Scanning electron microscopy (SEM) and speci? c surface
area(S
BET
4
). The photocatalytic activity of the prepared composites was investigated by the following removal of
Bismarck brown G (BBG) dye from its aqueous solutions. The obtained results showed that using MWCNTs in
combination with spinel oxide to produced composites (spinel/MWCNTs) which succeeded in increasing the activity
of spinel oxide and exhibited higher photocatalytic activity than spinel oxide alone. Also it was found that, multiwalled
carbon nanotubes were successful in increasing the adsorption and improving the activity of photocatalytic

degradation
of Bismarck brown G dye(BBG). The obtained results showed that spinel/MWCNTs
was more active

in
dye removal in comparison with each of spinel oxide and MWCNTs
alone under the same reaction conditions.

Also
band gap energies for the prepared composites showed lower values in comparison with neat spinel. This

point
represents a promising observation as these composites can be excited using a lower energy radiation sources.