Cationic dye adsorption and separation at discrete molecular level: first example of an iron cluster with rapid and selective adsorption of methylene blue from aqueous system. (5th January 2021)

• Record Type: Journal Article
• Authors: Akhtar, Muhammad Nadeem; I., Mantasha; Shahid, M.; AlDamen, Murad A.; Khalid, Muhammad; Akram, Muhammad
• Is Part Of: New journal of chemistry. Volume 45:Number 3(2021)
• Page Start: 1415
• Page End: 1422
• Publication Date: 2021-01-05
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d0nj05242f
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : A novel Fe6 cluster was designed as a rare example of any discrete molecule as a highly efficient, selective and rapid functional material for the adsorption of cationic dyes, i.e. methylene blue (MB), from contaminated water bodies. Abstract : A hexanuclear iron(iii ) complex, [Fe6 III (μ3 -O)(edteH)2 (piv)6 (N3 )2 ] (1 ), was prepared by the reaction of FeCl2 ·4H2 O with N, N, N ′, N ′-tetrakis(2-hydroxyethyl)ethylenediamine (H4 edte) and pivalic acid (Hpiv) in the presence of NaN3 in MeCN/CH2 Cl2 . Its X-ray structure determination demonstrated a centrosymmetric complex with two triangular [Fe3 (μ3 -O)] 7+ units. To verify the importance of this material, the adsorption study for 1 was performed. The use of 1 as a possible dye adsorbent was evaluated in an aqueous medium on two model dyes: methylene blue (MB) and methyl orange (MO). The results obtained indicated that 1 showed remarkable adsorption properties for MB (88.60%). This Fe cluster is the first example of a homometallic coordination cluster that presents an exciting adsorption property. The adsorption factor was that free O–H groups in the coordination cluster delivered O–H⋯π interactions through the MB dye, which was attributed to enhanced adsorption. The effects of various parameters, such as pH and temperature, were studied. The MB adsorption efficiency by adsorbent was ∼89% at neutral pH; however, for MO, it was ∼48% at the same pH. Also, MB adsorption at a higher temperature (40 °C) was ∼96%, whereas ∼61% for MO. The kinetic data provided a good confirmation of the adsorption pathways, i.e. the pseudo-second-order. Overall, this study disclosed an easy-to-prepare, stable, and reusable iron(iii ) cluster as a cost-effective, eco-friendly and efficient adsorbent for hazardous water-soluble aromatic dyes. This type of adsorbents can be fine-tuned further for the desired efficiency and dye selectivity.