Home >
News > Synthesis, Characterization, and Ammonia Adsorption Properties of Mesoporous Metal–Organic Framework (MIL(Fe))–Graphite Oxide Composites: Exploring the Limits of Materials Fabrication
Synthesis, Characterization, and Ammonia Adsorption Properties of Mesoporous Metal–Organic Framework (MIL(Fe))–Graphite Oxide Composites: Exploring the Limits of Materials Fabrication
Summary:
The authors from The City College of New York: developed a MIL-100(Fe)/graphite oxide (GO) composite material with enhanced ammonia adsorption properties, achieving significant results in the field of gas adsorption.
Background:
1. To address the problem of improving the stability and adsorption capacity of metal-organic frameworks (MOFs) in industrial applications, previous researchers conducted work on forming composites of MOFs with various substrates like polymers, alumina, and carbon nanotubes, achieving success in enhancing certain properties, yet there are problems with the complex structure of MOFs like MIL-100(Fe) that limit the proper formation of composites and affect their overall performance.
2. The authors in this study proposed an innovative method of synthesizing MIL-100(Fe) and GO composites with varying ratios and obtained results that shed light on the potential limits in the preparation of such composites as well as the ammonia adsorption process in MIL materials.
Research Content:
1. Synthesis:
The authors synthesized the MIL-100(Fe) and GO composites using a hydrothermal method with different ratios of the two components.
2. Characterizations:
1) Results of BET show that the MIL and MIL-GO1 samples have a surface area of about 1430 m²g⁻¹ and a total volume of pores of 0.750 cm³g⁻¹, while the MIL-GO2 sample has a surface area and total volume of pores about 20% smaller than those of MIL.
2) SEM tests show the particle size and morphology of the materials, with MIL exhibiting a well-defined octahedral crystal, MIL-GO1 having a less smooth surface, and MIL-GO2 showing smaller particles with a more irregular texture.
3) Other tests like X-ray diffraction, Fourier Transform infrared spectroscopy, and Raman spectroscopy were conducted to analyze the structure and composition of the composites.
3. Application:
The composites were tested for ammonia removal in dynamic conditions, and the results indicate that the MIL-GO1 composite has higher ammonia adsorption capacity than the physical mixture of MIL and GO, while the MIL-GO2 composite has lower capacity due to the detrimental effect of higher GO content on the crystallization of the MOF phase.
4. Mechanism:
The analysis of the experimental results shows that the main mechanism of ammonia retention in MIL-100(Fe) is via Brönsted interactions between ammonia and the water molecules present in the MOF, and the presence of excess water in the system lowers the acidity of the MIL material, causing a decrease in ammonia adsorption. The Lewis interactions between ammonia and the metal centers in MIL also play a role in the adsorption process.
Outlook：
This research highlights the challenges in preparing MIL-100(Fe)/GO composites and provides insights into the ammonia adsorption mechanism in MIL materials. The findings are significant for the development of MOF-based composites with improved performance in gas adsorption applications.
Synthesis, Characterization, and Ammonia Adsorption Properties of Mesoporous Metal–Organic Framework (MIL(Fe))–Graphite Oxide Composites: Exploring the Limits of Materials Fabrication
Authors: Camille Petit and Teresa J. Bandosz
DOI：10.1002/adfm.201002517
Link：https://onlinelibrary.wiley.com/doi/10.1002/adfm.201002517
The above review is for academic progress sharing. For any errors or copyright issues, please contact us for correction or removal.
