Preparation of 3-dimensional flower-like NiFe₂O₄ with enhanced adsorptive performance for water contaminants

In the work, 3-dimensional (3D) flower-like NiFe₂O₄ was prepared for the removal of water contaminants via a facile hydrothermal method and using Ni foam as substrate. The as-prepared NiFe₂O₄ was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Nitrogen adsorption-desorption, vibrating sample magnetometer and Fourier transformed infrared. The as-prepared NiFe₂O₄ owns a high specific surface which is favorable for adsorption of water contaminants. And the magnetic property of the as-prepared material, which is also preferred in wastewater treatment, makes it easy to be separated from the water. To investigate adsorption behavior, UV–visible spectrophotometer, adsorption isotherm and adsorption kinetics were studied. It is demonstrated that the adsorption process fits well with the Langmuir model and the pseudo-second-order model. The maximum adsorbing capacity (q_m) of the 3D flower-like NiFe₂O₄ for Congo red adsorption was 229.89 mg g⁻¹, and the adsorption capacity reached 80% in 10 min. The enhanced results suggest that the as-prepared 3D flower-like NiFe₂O₄ is a potential adsorbent for industrial wastewater treatment.