Facile synthesis of ZIF-8 nanoparticles using polar acetic acid solvent for enhanced adsorption of methylene blue

Abstract Synthesis of ZIF-8 using acetic acid (AA) as polar solvent produced uniform nanoparticles with enhanced adsorption properties for methylene blue removal. Morphology, structural properties and adsorption capacity of ZIF-8 nanoparticles were compared with ZIF-8 produced using N,N-dimethylformamide (DMF) solvent. ZIF-8 (AA) formed uniform nanoparticles with average diameter of 65 nm, significantly smaller than ZIF-8 (DMF) ~ 2 μm. The textural properties of ZIF-8 (AA) showed enhanced mesoporosity consisted of large pore diameter, 2.76 nm and mesopore volume, 0.166 cc/g with moderate 500 m2/g surface area, meanwhile ZIF-8 (DMF) showed microporous structure with high surface area of ~1000 m2/g. The effect of mesoporous features in enhancing methylene blue adsorption was evident by the high adsorption capacity on the ZIF-8 (AA) in comparison to ZIF-8 (DMF). Analysis of the adsorption data has demonstrated that the adsorption of methylene blue followed the pseudo-second order kinetic and the Langmuir model.