Enhanced methyl green adsorption of ZIF-۸ metal-organic framework: Insights from different solvents

This study investigates the effect of solvent type on the structural properties and adsorption performance of the ZIF-۸ metal-organic framework for removing various dyes including, methyl green (MG), methylene blue (MB), and methyl orange (MO) from water in acidic and alkaline environments. ZIF-۸ samples were synthesized using zinc nitrate, methylimidazole, and three different solvents including, water, methanol, and ethanol under atmospheric pressure and ۷۰ °C. Characterization using BET, XRD, FT-IR, and TGA techniques sheds light on the structural, chemical, and thermal properties of ZIF-۸ samples. Among the samples, ZIF-۸/M, synthesized using methanol, stands out, demonstrating the high surface area of ۲۱۷۲.۷ m۲/g, large total pore volume of ۱.۵۴۱۲ cm۳/g, and high crystallinity of ۳۱.۹% with improved thermal stability. Furthermore, ZIF-۸/M shows better adsorption performance for methyl green with a removal percentage of ۸۱.۹%, ۸۷.۱%, and an adsorption capacity of ۲۰.۵ mg/g and ۲۱.۸ mg/g, in acidic and alkaline environments, respectively. Enhanced dye adsorption of ZIF-۸/M is associated with both physical and effective chemical adsorption mechanisms via tuning the environment's acidity.This study investigates the effect of solvent type on the structural properties and adsorption performance of the ZIF-۸ metal-organic framework for removing various dyes including, methyl green (MG), methylene blue (MB), and methyl orange (MO) from water in acidic and alkaline environments. ZIF-۸ samples were synthesized using zinc nitrate, methylimidazole, and three different solvents including, water, methanol, and ethanol under atmospheric pressure and ۷۰ °C. Characterization using BET, XRD, FT-IR, and TGA techniques sheds light on the structural, chemical, and thermal properties of ZIF-۸ samples. Among the samples, ZIF-۸/M, synthesized using methanol, stands out, demonstrating the high surface area of ۲۱۷۲.۷ m۲/g, large total pore volume of ۱.۵۴۱۲ cm۳/g, and high crystallinity of ۳۱.۹% with improved thermal stability. Furthermore, ZIF-۸/M shows better adsorption performance for methyl green with a removal percentage of ۸۱.۹%, ۸۷.۱%, and an adsorption capacity of ۲۰.۵ mg/g and ۲۱.۸ mg/g, in acidic and alkaline environments, respectively. Enhanced dye adsorption of ZIF-۸/M is associated with both physical and effective chemical adsorption mechanisms via tuning the environment's acidity.

کلیدواژه ها:

ZIF-۸ ، Metal-organic framework ، Solvent effect ، Dye adsorption ، Methyl green