Facile one-pot synthesis of urchin-like Fe–Mn binary oxide nanoparticles for effective adsorption of Cd(ii) from water

摘要

The development of efficient and low-cost adsorbent is critical for water treatment, but still presents great challenges. Herein, we report the synthesis of three-dimensional (3D) hierarchical nanostructured adsorbent, urchin-like Fe–Mn binary oxides (UFMBO), by simple heating without any template/surfactant. The surface morphology, crystalline and pore structure were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption–desorption isotherm, respectively. Results revealed that the UFMBO had a 3D hierarchical nanostructure with a high specific surface area of 142 m ~(2) g ~(?1) , which was conducive to pollutant adsorption and adsorbent separation. Cd( II ) removal using the UFMBO was evaluated by batch adsorption experiments. The adsorption equilibrium was established within 3 h, and the adsorption process was better described by pseudo second-order kinetics model. The adsorption isotherm data fitted well to Langmuir model, and the maximum adsorption capacity was 74.76 mg g ~(?1) at pH 6.0. Influence by ionic strength on the adsorption was significant, implying that Cd( II ) may form outer-sphere complexes on the adsorbent surface. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis suggested hydroxyl group played an important role in Cd( II ) uptake. The highly effective 3D UFMBO adsorbent can be easily separated and regenerated, demonstrating its great potential in cadmium removal from contaminated water source.