Efficiency and selectivity of cost-effective Zn-MOF for dye removal, kinetic and thermodynamic approach

Abstract

Green synthesis of metal–organic frameworks (MOFs) has attracted a lot of attention as a crucial step for practical industrial applications. In this work, green synthesis of zinc(II) metal–organic framework (Zn-MOF) has been carried out at room temperature. The Zn metal (node) was extracted from spent domestic batteries, and the linker was benzene di-carboxylic acid (BDC). The characterization of the as-prepared Zn-MOF was accomplished by PXRD, FT-IR spectroscopy, SEM, TEM, TGA, and nitrogen adsorption at 77 K. All the characterization techniques strongly supported that as-synthesized Zn-MOF using metallic solid waste Zn is similar to that was reported in the literature. The as-prepared Zn-MOF was stable in water for 24 h without any changes in its functional groups and framework. The prepared Zn-MOF was tested for the adsorption of three dyes, two anionic dyes, aniline blue (AB), and orange II (O(II)) as well as methylene blue (MB), an example of cationic dye from aqueous solution. AB has the highest equilibrium adsorbed amount, qe, of value 55.34 mg g−1 at pH = 7 and 25 °C within 40 min. Investigation of the adsorption kinetics indicated that these adsorption processes could be described as a pseudo-second-order kinetic model. Furthermore, the adsorption process of the three dyes was described well by the Freundlich isotherm model. According to the thermodynamic parameters, the adsorption of AB on the prepared Zn-MOF was an endothermic and spontaneous process. In contrast, it was non-spontaneous and exothermic for the uptake of O(II) and MB. This study complements the business case development model of “solid waste to value-added MOFs.”

Adsorptive Elimination of a Cationic Dye and a Hg (II)-Containing Antiseptic from Simulated Wastewater Using a Metal Organic Framework

“…The removal efficiency of the pollutants increased with an increase in the amount of adsorbent (from 250 to 2000 mg/L) and was found to be maximum (95.01% and 90.80% for safranin O and merbromin, respectively) at an adsorbent concentration of 2000 mg/L. This result was obvious, as the increase in the amount of adsorbent provided a greater number of adsorption sites for capturing the adsorbate molecules during the adsorption process, which ultimately enhanced the adsorption [ 49 ].…”

“…The ΔG value is important because it indicates whether the adsorption is physisorption or chemisorption. If the ΔG value is negative and ranging from 0 to 20 kJ/mol, then it is physisorption, and if it is negative within the range of 80 kJ/mol to 400 kJ/mol, then it is chemisorption [ 60 ]; however, the ΔG° value varied from −3.8 to −4.2 kJ/mol for safranin O and from −3.4 to −3.8 kJ/mol for merbromin, and in both cases, the negative ΔG value was lower than 20 kJ/mol; hence, the adsorption process was physisorption [ 49 , 61 ]. Here, Δ S was highly positive, indicating that during the adsorption process, the degrees of freedom increased at the solid–liquid interface [ 45 ].…”

Highly enhanced cationic dye adsorption from water by nitro-functionalized Zn-MOF nano/microparticles and a biomolecular binder for improving the reusability

“…[26][27][28][29][30][31][32][33] The high surface area and tunable porosity with tailorable functionality of MOFs are highly desired for adsorption of dyes from water. [34][35][36][37][38] Ethylenediamine-grafted MIL-101 exhibited higher MO dye adsorption compared to the MIL-53 MOF due to the increased electrostatic interactions between methyl orange (MO) and the adsorbent. 39 Fe-terephthalate MOFs exhibited strong anionic MO and cationic MB adsorption.…”

Removal of Dibenzothiophene from Liquid Fuels by Photocatalytic Desulfurization over Zn‐Terephthalate Complex: A Process Modelling and Optimization by Response Surface Methodology

“…[14,15] Zn-terephthalate MOF or Zn-(BDC) MOF has been reported as a catalyst for the synthesis or oxidation of alcohols. [16,17] According to the literature review, so far Zn-MOFs have not been used as a photocatalyst in the desulfurization of Saromatics in fuels. In this work, for the first time, the Znterephthalate Complex with the structure of Zn-(BDC) MOF was developed as a photocatalyst for photocatalytic desulfurization of DBT from the fuel model.…”

“…In the field of fuel treatment, MOFs have been used as adsorbents for the desulfurization process [14,15] . Zn‐terephthalate MOF or Zn‐(BDC) MOF has been reported as a catalyst for the synthesis or oxidation of alcohols [16,17] …”