Selective and Recyclable Congo Red Dye Adsorption by Spherical Fe3O4 Nanoparticles Functionalized with 1,2,4,5-Benzenetetracarboxylic Acid

Sobhan Chatterjee,Sarathkumar Krishnan,Amrendra K Singh,Dhirendra K Rai,Pradeep Mathur,Nikita Guha

doi:10.1038/s41598-019-57017-2

Sobhan Chatterjee, Sarathkumar Krishnan + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-57017-2

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Journal: Scientific Reports	Publication Date: Jan 10, 2020
Citations: 105	License type: open-access

Affiliation: Indian Institute of Technology Indore

Abstract

In this study, the new material Fe3O4@BTCA has been synthesized by immobilization of 1,2,4,5-Benzenetetracarboxylic acid (BTCA) on the surface of Fe3O4 NPs, obtained by co-precipitation of FeCl3.6H2O and FeCl2.4H2O in the basic conditions. Characterization by P-XRD, FE-SEM, and TEM confirm Fe3O4 has a spherical crystalline structure with an average diameter of 15 nm, which after functionalization with BTCA, increases to 20 nm. Functionalization also enhances the surface area and surface charge of the material, confirmed by BET and zeta potential analyses, respectively. The dye adsorption capacity of Fe3O4@BTCA has been investigated for three common dyes; Congo red (C.R), Methylene blue (M.B), and Crystal violet (C.V). The adsorption studies show that the material rapidly and selectively adsorbs C.R dye with very high adsorption capacity (630 mg/g), which is attributed to strong H-bonding ability of BTCA with C.R dye as indicated by adsorption mechanism study. The material also shows excellent recyclability without any considerable loss of adsorption capacity. Adsorption isotherm and kinetic studies suggest that the adsorption occurs by the Langmuir adsorption model following pseudo-second-order adsorption kinetics.

Highlights

Besides electrostatic interactions as applicable to the cases mentioned above, the adsorption of dye is actively facilitated by hydrogen bonding, which depends on functional groups and active coordination sites present on the solid surface
We have explored a multi carboxylate organic ligand 1,2,4,5-Benzentetracarboxylic acid (BTCA) for surface functionalization of Fe3O4 nanoparticles for rapid and selective adsorption of a ubiquitous industrial pollutant Congo red dye
A new Fe3O4@BTCA material has been synthesized by surface functionalization of Fe3O4 NPs with 1,2,4,5-Benzenetetracarboxylic acid for rapid and selective adsorption of Congo red dye in an aqueous medium

Summary

Introduction

Besides electrostatic interactions as applicable to the cases mentioned above, the adsorption of dye is actively facilitated by hydrogen bonding, which depends on functional groups and active coordination sites present on the solid surface. The ability of Fe3O4@BTCA to adsorb dyes on to its surface, leading to the color removal of aqueous dye solutions was investigated towards C.R (Congo red), M.O (Methyl Orange), and C.V (Crystal Violet) by UV-Vis absorption spectroscopy.

Results

Conclusion