A green method to synthesize flowerlike Fe(OH)3 microspheres for enhanced adsorption performance toward organic and heavy metal pollutants

Dyestuffs and heavy metal ions in water are seriously harmful to the ecological environment and human health. Three-dimensional (3D) flowerlike Fe(OH)3 microspheres were synthesized through a green yet low-cost injection method, for the removal of organic dyes and heavy metal ions. The Fe(OH)3 microspheres were characterized by thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) techniques. The adsorption kinetics of Congo Red (CR) on Fe(OH)3 microspheres obeyed the pseudo-second-order model. Cr6+ and Pb2+ adsorption behaviors on Fe(OH)3 microspheres followed the Langmuir isotherm model. The maximum adsorption capacities of the synthesized Fe(OH)3 were 308, 52.94, and 75.64mg/g for CR, Cr6+, and Pb2+ respectively. The enhanced adsorption performance originated from its surface properties and large specific surface area of 250m2/g. The microspheres also have excellent adsorption stability and recyclability. Another merit of the Fe(OH)3 material is that it also acts as a Fenton-like catalyst. These twin functionalities (both as adsorbent and Fenton-like catalyst) give the synthesized Fe(OH)3 microspheres great potential in the field of water treatment.