Biocatalyst Based on Magnetic Nanoparticles with Cu(II), Mn(II), Zn(II) and Immobilised Catalase

This article described a process for the preparation of a Fe3O4 nanocatalyst modified with Mn(II), Cu(II) and Zn(II) ions immobilised with catalase. The effectiveness of the description of the ion sorption process was compared with four equilibrium models: Langmuir, Freundlich, Redlich-Peterson and Sips. The proposed models allow the description of both single- and multi-component sorption. The results were also verified by DFT analysis. The Langmuir model describing single-component sorption and the extended Langmuir model for multi-component systems with the best fit represented the sorption of metal ions on Fe3O4. The maximum sorption capacity values in the pseudo-second-order kinetic model were 10.76, 12.87 and 10.52 mg/g for Cu(II), Zn(II) and Mn(II) in the single-component systems and 11.79, 8.54 and 2.03 mg/g for Cu(II), Zn(II) and Mn(II) in the multi-component system, respectively. The kinetics parameters were described most accurately by a pseudo-second-order model, which suggested, along with the Extended Langmuir model, the chemical nature of the sorption. After preparation of the Fe3O4/Mn-Zn-Cu material, catalase was immobilised on the surface of the material. The final material was able to decompose hydrogen peroxide with an activity of 7130 units/g of material. Modification of the material with Mn(II), Cu(II) and Zn(II) resulted in an increase in H2O2 removal efficiency exceeding 99.9%.

Automated summary

This article presents a method for synthesizing a Fe3O4 nanocatalyst modified with Mn(II), Cu(II) and Zn(II) ions, and immobilized with catalase. The sorption process of metal ions on Fe3O4 is described using four equilibrium models, including Langmuir and Freundlich models. The proposed models accurately describe both single- and multi-component sorption. The kinetics of the sorption process and the effectiveness of the material in decomposing hydrogen peroxide were also evaluated.