This book is focused on the preparation of a MWCNTs/P25 composite and analyzing the prepared composite using different techniques. The adsorption capability of the MWCNTs and the photocatalytic activity of the synthesized MWCNTs/P25 samples were quantified in terms of their adsorption capacity and the photocatalytic degradation of organic dye. This research consists of three main parts. In the first part the MWCNTs/P25 composite was synthesized using simple evaporation and a drying process. In the second part the structural morphological and chemical properties of the synthesized MWCNTs/P25 composite were investigated by different analytical techniques such as Raman spectroscopy X-ray diffraction (XRD) Fourier transform infrared spectroscopy (FTIR) UV-visible diffuse reflectance spectroscopy and a scanning electron microscope (SEM). In the third part two models of applications were performed: The adsorption capacity of an aqueous solution of Bismarck brown R (BBR) was used as a model of wastewater to study the treatment activity of MWCNTs and MWCNTs/P25.