A Study on the Adsorption of Methylene Blue on Polydopamine@Zeolitic Imidazolate-67 in Aqueous Solution

Polymer-modified metal organic frameworks (mofs) can enhance water purification processes by offering increased adsorption capacity, making them highly effective in separating pollutants from contaminated water. in this research, a facile and low-cost route was used to prepare polydopamine@zeolitic imidazolate framework-67 (pda@zif-67). the structure, morphology, surface functional groups and particle size distribution of pda@zif-67 was studied using fourier-transform infrared spectroscopy (ftir), field emission scanning electron microscopy (fesem), energy dispersive spectroscopy (eds), and brunauer-emmet-teller (bet) analyses. the specific surface area and pore diameter of pda@zif-67 nanoparticles were found to be 203.78 m2/g and 4.179 nm, respectively. the pda@zif-67 was used as an adsorbent for removal of methylene blue dye from aqueous solution. the results showed that the maximum adsorption capacity of pda@zif-67 for removal of mb was achieved at ph 2, 65 °c, 10 mg of adsorbent, and methylene blue concentration of 7.5 ppm. moreover, the adsorption process isotherms, thermodynamics, and kinetics were studied to ascertain the adsorption mechanism. the methylene blue molecules located in the fine pores of the pda@zif-67 adsorbent determine the adsorption rate. moreover, it was found that the adsorption process of methylene blue at elevated temperature is a spontaneous and endothermic reaction. the adsorption capacity of pda@zif-67, after six recovery cycles decreased to 62.21%, which can be considered as an excellent advantage for this adsorbent.