Synthesis of highly stable MOF-5@MWCNTs nanocomposite with improved hydrophobic properties

Abstract

Metal-organic frameworks (MOFs) are a promising class of nanoporous crystalline materials with potential applications in gas storage, catalysis, biomedical and clean energy. However, moisture adsorption dampens their structure and therefore capacity and selectivity. Improving the hydrostability of MOF-5 without compromising on its characteristic features can be a potential way to make the best use of this material. In this work, we used a solvothermal method to precipitate MOF-5 in well-dispersed carboxy derived MWCNTs. By inspiring from the hydrophobic properties of carbon nanotubes (CNTs), we have successfully utilized a solvothermal approach to precipitate MOF-5 in well-dispersed carboxy functionalized multiwalled carbon nanotubes (FMWCNTs) to produce a MOF-5@FMWCNTs nanocomposite. The experimental results in this study reveal that the FMWCNTs form stable nanocomposite with MOF-5 particles and the resultant hybrid MOF-5@FMWCNTs nanocomposite indicated an increase in the moisture stability and even after prolonged exposure to ambient moist environment (55% humidity at 28 °C) showed less degradation as confirmed by the BET surface area, and powder XRD studies. So, our findings demonstrate a simple synthetic route to make use of FMWCNTs to stabilize the MOF-5 and it can be a choice for many other MOFs without much compromise on the surface area.

Keywords

• Metal-organic frameworks (MOFs)
• Carbon nanotubes
• Aspect ratio
• Nanocomposite
• Molecular statics simulations