In this study, the synthesis of copper-based multi-walled carbon nanotube composites is described. Over the last years, carbon nanotubes (CNTs) have been widely used in many scientific research fields and have found applications in several sectors, e.g. for water treatment. This work focuses on combining the exceptional characteristics of CNTs, such as high specific surface area and antibacterial properties, with the antimicrobial/ antivirus features of copper oxides. The influence of synthesis parameters and thermal treatment on the final product was studied. Copper leakage was evaluated at both pH 5 and pH 7, confirming the possibility of applying Cu-based MWCNT composites in water filtration systems.