Kinetics, Thermodynamics, and Modeling of Amido Black Dye Photodegradation in Water Using Co/TiO2 Nanoparticles

Titanium oxide nanoparticles were doped with copper and characterized by XRD, FT-IR, TEM, and SEM. The surface morphology was spherical with 15-26 nm as particle size. The doped titanium oxide (Co/TiO2) nanomaterial was used for photodegradation of amido black dye in water. The maximum photodegradation of amido black obtained was 90%. The values of free energy and enthalpy were negative, indicating spontaneous photodegradation of amido black dye. The photodegradation of amido black dye obeyed first-order kinetic model. The photodegradation mechanism of amido black involved adsorption of the dye on the surface of cobalt doped titanium oxide and its degradation under UV radiation. The electron (e(-)) and hole (h(+)) pairs were generated by Co/TiO2, which consequently generated superoxide oxygen anion and hydroxyl free radical. These species degraded amido black dye. The reported method was fast, effective, and economic, which may be utilized to remove amido black in water. The doped TiO2 catalyst was quite stable and can be used up to 5 cycles.