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 selfassembled 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), N 2 sorption, and X-ray photoelectron spectroscopic (XPS) studies. N 2 sorption analysis revealed high surface areas (74−152 m 2 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 Hg 2+ adsorption. The adsorption process has been discussed using Langmuir and Freundlich models. These self-assembled mesoporous α-FeOOH nanoparticles can act as a very efficient and reusable adsorbent for Hg 2+ from polluted water.

New Sustainable, Scalable and One-Step Synthesis of Iron Oxide Nanoparticles by Ion Exchange Process

“…From Figure 3 , we can also observe that, except for S1 N2 sample where the hexagonal lamellas could derive from a self-assembling of primary nanoparticles [ 15 , 34 , 35 ], the other samples exhibit that the nanoparticles are monodisperse, as shown in the insets. This result can be strongly related to the fact that, during the synthesis, for all the samples a fast and diffuse nucleation occurs, and all the crystallites form at the same time and under the same environment, in the whole volume of reaction.…”

“…SEM images, shown in Figure 5 , put in evidence the aggregation behavior, in relation to the different morphologies characterizing each sample. The δ-FeOOH sample S1 N2 denotes spherical aggregations organized in an ordered network of nano-platelets, all having thicknesses < 20 nm, forming flower-like particles [ 35 ], as shown in Figure 5 a. In addition, this network presents both macropores and mesopores, and it results in being characterized by a high whole porosity.…”

Reductant‐Free Synthesis of Silver Nanoparticles by Functionalized Hollow Doughnut Mesoporous Silica Nanoparticles for Preparation of Catalytic Nanoreactor

“…The N 2 adsorption/desorption isotherms and pores size distribution of hd‐MSN and Ag/hd‐MSN‐NH 2 are shown in Figure . It can be seen that both samples showed similar IV isotherms and typical H1 hysteresis loops, indicating the properties of a typical mesoporous material . And the surface area values were 645 m 2 g −1 and 450 m 2 g −1 corresponding to hd‐MSN and Ag/hd‐MSN‐NH 2 , respectively.…”

Development of hollow δ-FeOOH structures for mercury removal from water

“…Iron oxyhydroxide (FeOOH) nanoparticles are cheap, harmless and eco-friendly (Patra & Kim 2017), and used widely for efficient removal of various metals from aqueous media (Kokkinos et al 2015). Iron hydroxides have been used widely as decontaminants to remove oxyanions like arsenite, arsenate, chromate, vanadate, phosphate, etc (Davantès et al 2016).…”