Removal of acid red 94 and methylene blue using iron-polyphenol nanomaterials synthesized by various plant leaves: A comparison study

This paper investigated the removal of acid red 94 and methylene blue from aqueous solution using iron-polyphenol nanomaterial synthesized by eucalyptus, rosemary and diosma leaves. The iron-poyphenol material was characterized by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The kinetics, sorption equilibrium and thermodynamic data were analysed to understand dyes´ removal behaviours. It found that ironpolyphenol nanomaterials synthesized by different plants present different characteristics regarding morphology, colour and adsorption capacity. TEM images showed that the freshly synthesized Fe-polyphenol material took the form of nanoparticles and then became cross-linked polymers in aged colloid. They can effectively remove acid red 94, but were less effective in removing methylene blue due to surface charge. The causes of these behaviours are discussed in this paper. It confirmed that Fe-polyphenol nanomaterial is a promising adsorbent for removing some contaminants from water.