Cadmium‐based metal–organic framework for removal of dye from aqueous solution

Abstract

AbstractMetal–organic framework ([Cd2(oba)2(4‐bpdb)2] n·3.5(DMF)) (TMU‐8) was successfully synthesized via mechanosynthesis by using nonlinear dicarboxylate and linear N‐donor. The TMU‐8 exhibited accessible cages and tunnels, specific adsorption making it excellent adsorbent for dye removal. The obtained TMU‐8 exhibited accessible cages and tunnels, specific adsorption making them excellent adsorbent for dye removal. The adsorption isotherms, kinetics, thermodynamics, and spectroscopic analyses of the removal of the reactive black 5 onto TMU‐8 were studied. Several variables affecting the removal of the reactive black 5, such as sample pH, amount of sorbent, contact time, and salt concentration, were investigated and optimized. The thermodynamic parameters and kinetics characteristics were also analyzed. The thermodynamic parameters and kinetics characteristics were analyzed. The experimental isotherms data were fitted into Freundlich, Temkin, and Langmuir isotherm equations, and the results indicated that the Langmuir isotherm described the data appropriable than others for reactive black 5 adsorptions. The qmax (mg g−1) was calculated from the Langmuir as 79.36 mg g−1. The fitness of equilibrium data to kinetic models such as, pseudo‐first‐order and pseudo‐second‐order were studied. The adsorption followed pseudo‐second‐order kinetics. Thermodynamic parameters like the enthalpy, entropy, and Gibbs free energy were determined by the Gibbs free energy function, confirming that the adsorption process was spontaneous, exothermic, and feasible.