Carbon cryogel preparation and characterization

The carbon cryogels (CCs) show significant potential for application in a wide variety of applications, from absorbents and catalysts to supercapacitors and fuel cells, due to their high specific surface area, multimodal pore-size distribution, electrical conductivity, and thermo-mechanical stability. In the present study, the CC material was prepared by a sol-gel process from resorcinol with formaldehyde and heat treatment in an inert atmosphere. The Brunauer Emmett Teller (BET) measurements, X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), differential thermal analysis with thermogravimetric measurements (DTA-TG), scanning electron microscopy (SEM), and small-angle X-ray scattering (SAXS) analysis, as complementary techniques, were used to characterize the obtained CC. It was found that the obtained CC is a porous amorphous material with high open porosity (≈82.5%) and complex porous structure organization. Using the small-angle neutron scattering (SANS) with the contrast variation technique and the adsorption of deuterated water by carbon cryogel it was possible to separately study the structure of open and closed pores, as well as to estimate both the volume fraction of closed pores (φclose pore ≈ 1%) and the total porosity (φtotal ≈ 83.5%) of the obtained CC. [Display omitted] •Carbon cryogel (CC) was prepared by polymerization, freeze-drying and pyrolysis.•Amorphous CC with high open porosity and complex porous structure was attained.•BET, SEM, XRD, Raman, SAXS and SANS techniques were used for CC characterization.•Total CC porosity of 83.5% with 1% volume fraction of closed pores was achieved.•Three-modal size distribution of open non-spherical mesopores was detected.