High-surface-area Ficus leaf-extracted CuO-ZnO-NiO ternary nanocomposites for rapid adsorption-assisted UV-A degradation of Direct Blue 15

Kafa’a H. Ali, Department of Biochemical Engineering, Al-Khwarizmi College of Engineering, University of Baghdad, Baghdad, Iraq;Follow
Mohammed A. Atiya, Department of Biochemical Engineering, Al-Khwarizmi College of Engineering, University of Baghdad, Baghdad, Iraq;
Ahmed K. Hassan, Scientific Research Commission, Research and Technology Center of Environment, Water and Renewable Energy, Baghdad, Iraq.

Abstract

Direct Blue 15 (DB15) is a long-lasting synthetic dye that pollutes water and is difficult to remove during wastewater treatment. Conventional treatments fail to remove DB15 adequately due to rapid electron-hole recombination, which necessitates photocatalysts with reduced recombination rates for effective dye removal. The study aims to synthesize and evaluate a CuO-ZnO-NiO ternary system as an integrated adsorption and UV-A photocatalysis platform for DB15 removal. Ficus leaf-extracted CuO-ZnO-NiO nanocomposites with four Cu:Zn:Ni ratios (1:1:1, 1:1:2, 1:2:1, 2:1:1) were prepared by co-precipitation, followed by extensive chemical and physical characterization and dye-removal performance measurements. The CuO-ZnO-NiO nanocomposite exhibited hexagonal zinc oxide, cubic nickel oxide, and monoclinic copper oxide phases, with mixed morphologies and a mean particle size of 56.75 nm. The nanocomposite had a specific surface area of 34.741 m² g⁻¹ and a total pore volume of 0.089 cm³ g⁻¹. Among the four ratios, the 1:1:1 Cu:Zn:Ni nanocomposite delivered the highest overall performance, achieving complete DB15 removal by adsorption at 20 mg L⁻¹ and complete DB15 degradation by UV-A photocatalysis at 30 mg L⁻¹, both within 150 min. Reuse tests of the nanocomposite over five consecutive cycles yielded DB15 degradation efficiencies of 95%, 93%, 91%, 63%, and 59%. Kinetic and equilibrium analyses indicated pseudo-second-order behaviour and Langmuir-type adsorption, and thermodynamic parameters indicated a spontaneous, endothermic adsorption process. Ficus-based CuO-ZnO-NiO nanocomposites enable high DB15 degradation through complementary adsorption and UV-A photocatalytic pathways and support practical wastewater treatment applications.

Recommended Citation

Ali, Kafa’a H.; Atiya, Mohammed A.; and Hassan, Ahmed K. (2026) "High-surface-area Ficus leaf-extracted CuO-ZnO-NiO ternary nanocomposites for rapid adsorption-assisted UV-A degradation of Direct Blue 15," Karbala International Journal of Modern Science: Vol. 12 : Iss. 2 , Article 11.
Available at: https://doi.org/10.33640/2405-609X.3463