New Porous Heterostructures Based on Organo-Modified Graphene Oxide for CO2 Capture.

Eleni Thomou,Efstratia Mitsari,Petra Rudolf,Konstantinos Spyrou,Estela Moretón Alfonsín,Evmorfia K Diamanti,Lamprini G Boutsika,Oreste De Luca,Apostolos Enotiadis,Andreas Sapalidis,Dimitrios Gournis

doi:10.3389/fchem.2020.564838

Abstract

In this work, we report on a facile and rapid synthetic procedure to create highly porous heterostructures with tailored properties through the silylation of organically modified graphene oxide. Three silica precursors with various structural characteristics (comprising alkyl or phenyl groups) were employed to create high-yield silica networks as pillars between the organo-modified graphene oxide layers. The removal of organic molecules through the thermal decomposition generates porous heterostructures with very high surface areas (≥ 500 m2/g), which are very attractive for potential use in diverse applications such as catalysis, adsorption and as fillers in polymer nanocomposites. The final hybrid products were characterized by X-ray diffraction, Fourier transform infrared and X-ray photoelectron spectroscopies, thermogravimetric analysis, scanning electron microscopy and porosity measurements. As proof of principle, the porous heterostructure with the maximum surface area was chosen for investigating its CO2 adsorption properties.

Highlights

The dramatic effects of global warming and the constant degradation of our planet are among the most important and challenging issues the modern world is facing
The basal spacing, d001, of the org-Graphene oxide (GO) shifts to 18.4 Å corresponding to an interlayer separation of = 18.4–6.1 = 12.3 Å, where 6.1 Å is the thickness of the GO monolayer (Dekany et al, 1998)
The presence of nitrogen from the intercalated dodecylamine for GO was treated with the TEOS (GO-TEOS), GO-APTEOS and GO-BTB is confirmed by the N1s photoemission lines, shown in Figures 8D–F; note that its position in binding energy at approximately 400.0 eV indicates that there is no C-N-C bond, which would give rise to a spectral signature at lower binding energies, but that the amines prefer to bind electrostatically with the oxygen groups of the graphene oxide (Cecchet et al, 2003)

Summary

INTRODUCTION

The dramatic effects of global warming (sea level rise, wildfires, flooding, extreme weather conditions) and the constant degradation of our planet are among the most important and challenging issues the modern world is facing. Pillaring of 2-D layered materials allows for a fine control of the structural characteristics of the resulting micro- and nanoporous composites (Ohtsuka, 1997) and assures structural stability, permanent pore sizes and high surface areas. Such rational interlayer design has opened new prospects for applications in areas as diverse as the nanocomposites themselves (Nicotera et al, 2011; Enotiadis et al, 2013; Zapata et al, 2013), namely catalysis (Kloprogge et al, 2005; Gil et al, 2008), metal uptake (Balomenou et al, 2008), sensors (Tonlé et al, 2007), environmental remediation (Zhao et al, 2011), supercapacitors (Yan et al, 2012; Ke and Wang, 2016; Banda et al, 2019) and Lithium-ion batteries (Hu et al, 2019). Before exposure to CO2 the samples were outgassed overnight in 250 ◦C under high vacuum (10−8 mbar) until the mass was observed to remain constant

RESULTS AND DISCUSSION

CONCLUSIONS

DATA AVAILABILITY STATEMENT