Removal of chromium (VI) heavy metal from aqueous solution by metal
organic frameworks ([Zn(BTC)(DMF)] and [Co(BTC)(DMF)]) and carrot-
derived carbon dots
Dimaral Aben, Yerkezhan Amangeldinova, Mannix Balanay*
Department of Chemistry, School of Science and Technology, Nazarbayev University,
Astana, Kazakhstan
Email: [email protected], [email protected]
Abstract
This study reports a novel nanostructured adsorbent material that was synthesized by the
solvothermal method using metal organic frameworks (MOF [Zn(BTC)(DMF)] and
[Co(BTC)(DMF)]) and carrot-derived carbon dots for the adsorption of chromium (VI) ions
from aqueous solution. The morphology, the structural properties and the adsorption
experiments of hexavalent chromium using the prepared Zn-MOF(TMA), Co-MOF(TMA),
Zn-MOF(TMA)@CD and Co-MOF(TMA)@CD powders were characterized by scanning
electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), N 2
porosimeter, and UV-Visible spectroscopy respectively. As the main goal of this study, we
investigated the adsorption capacity of hexavalent chromium and the efficiency of two types
of MOFs and MOF@CDs (Zn and Co) were compared. Experimental parameters such as pH
of solution and contact time and their effects were analyzed. The results showed that the
Chromium (VI) removal percentage was higher for MOF@CDs than for MOFs and this trend
can be explained in terms of surface area (SA). MOF@CDs (SA = 4.927 m²/g for Zn-
MOF@CD and SA = 3.223 m²/g for Co-MOF@CD) and have more holes where chromium
(VI) could be trapped inside of them. Moreover, the slightly higher amount of adsorption
capacity observed for the 15 minutes stirring time and pH 4 solution of Cr (VI).
Reference
1. Melvin, S. S.; Subramaniyan, V.; Bhattacharya, J.; Parthiban, C.; Chand, S.; Pradeep Singh, N. D.
Composites Part B 152 (2018), 116-125.