Synthesis of carbon nanotube/cobalt ferrite nanocomposites and theinvestigation of their photocatalytic activities

Water is an indispensable and irreplaceable resource for all living things. However, water pollution by chemical pollutants from various sources or by microbial effects, is one of the biggest environmental problems of our age. Traditional treatment methods may be insufficient for the removal of pollutants from water. Therefore, it is necessary to develop new treatment methods or improve existing methods for water treatment. Accordingly, nanotechnology offers essential alternative solutions to water pollution problems. In recent years, photocatalytic oxidation methods performed with various nano-sized semiconductors used as photocatalysts, have attracted great deal of interest in wastewater treatment. In this study, the photocatalytic activities of cobalt ferrite/CNT nanocomposites were investigated for the treatment of textile industry wastewater. Firstly, magnetic cobalt ferrite nanoparticles were synthesized by the hydrothermal synthesis method. Then, to increase the photocatalytic activities of the synthesized particles, two different composites were obtained by immobilizing on single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT). The various structural, magnetic and morphological properties of all obtained samples were comprehensively characterized by using multiple techniques such as XRD, TEM, FT-IR, BET, and VSM. Later, CoFe 2 O 4 nanoparticles, CoFe 2 O 4 @SWCNT, and CoFe 2 O 4 @MWCNT nanocomposites were used as photocatalysts in treatment via the photocatalytic oxidation of synthetically prepared model wastewaters containing 50 mg/L dyestuffs, and their photocatalytic activities were comparatively investigated. Experiments were carried out at catalyst dosages of 0.010 g/L, 0.025 g/L, 0.050 g/L, and 0.10 g/L for each catalyst, respectively. The results obtained from the experiments show that the dye content in the aqueous solution was entirely removed. Additionally, calculations made using the experimental data obtained showed that all these processes were compatible with the pseudo- first-order kinetic model.