Exploring the Impact of Solvent Choice on the Synthesis and Properties of ZIF-8 Nanoparticles

抄録

Introduction:

Zeolitic imidazolate frameworks (ZIFs) have gained prominence due to properties like surface area, tunable pores, and stability. Among ZIFs, ZIF-8, composed of zinc ions and 2-methylimidazolate (Hmim) ligands, stands out. Synthesis choices impact ZIF-8 properties. The use of methanol, while effective, presents several concerns. It is flammable, toxic, and sourced from non-renewable resources, hence raising issues of safety, environmental impact, and sustainability. These challenges necessitate the exploration of safer and more environmentally friendly alternatives to methanol. Water seems viable, but its use is not straightforward, demanding a thorough investigation. This study addresses water-based ZIF-8 synthesis challenges and compares its properties with methanol. By analyzing physicochemical attributes and precursor ratios, we seek optimal synthesis routes, enhancing ZIF-8 performance.

Results:

Yield increases with molar ratio growth for aqueous and methanolic solutions. Water-based ZIF-8 samples exhibit higher yields, partly due to higher molecular weight compounds. XRD patterns confirm ZIF-8 and a new structure for aqueous samples, identified as ZIF-L. Methanol's acidity favors ZIF-8 formation, giving methanolic samples higher ZIF-8 yields. Crystallite sizes decrease with higher ratios. Methanol's suitability for ZIF-8 synthesis is confirmed.

Conclusions:

This study aims beyond solvent comparison, exploring fundamental traits for optimized water-based synthesis. ZIF-L and methanolic ZIF-8 production under specific conditions are demonstrated. Proposed mechanisms align with the results. This work advances eco-friendly MOF synthesis, contributing to green chemistry discourse.

References:

1. Tezerjani et al. Different solvent effects on zeolitic imidazolate framework-8 synthesis, RSC Adv. 11, 19914 (2021).

2. Jian et al. Water-based synthesis of ZIF-8 with high morphology, RSC Adv. 5, 48433 (2015).

3. Ahmad et al. Enhanced performance of amine-functionalized ZIF-8-decorated GO for ultrafiltration, Separation and Purification Technology 239, 116554 (2020).