Smart Design of Self-Assembled Mesoporous α-FeOOH Nanoparticles: High-Surface-Area Sorbent for Hg2+ from Wastewater

Abstract

Self-assembled mesoporous α-FeOOH nanoparticles with high surface area and controlled structure have been synthesized through a simple and environmentally friendly method. The formation mechanism of self-assembled mesoporous structures, as well as the effect of pH on the structure of the materials, is carefully discussed. The self-assembled mesoporous α-FeOOH nanoparticles have been characterized by small-angle X-ray scattering (SAXS) analysis, powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 sorption, and X-ray photoelectron spectroscopic (XPS) studies. N2 sorption analysis revealed high surface areas (74–152 m2 g–1) and narrow pore size distributions (2.5 nm) for different samples. The XPS analysis revealed that the materials contain a large amount of surface Fe–OH groups which are the active suite for Hg2+ adsorption. The adsorption process has been discussed using Langmuir and Freundlich models. These self...