Chemically reduced graphene oxide based aerogels - Insight on the surface and textural functionalities dependent on handling the synthesis factors

Efficient adjusting of reduced graphene oxide aerogels properties requires information about experimental factor-aerogel property relationship. In this work, the reduced graphene oxide aerogels surface and textural functionalities in relation to precursor concentration, gelation time and hydrogel freezing temperature were studied in detail, with the use of dynamic adsorption method of gaseous organic probes and experimental design. The precursor concentration and the hydrogel freezing temperature have the strongest influence on textural properties - a negative correlation with apparent surface area was observed. The highest value of 229.36 m(2) g(-1) was obtained for samples synthesized at the lowest concentration of precursor (2 mg mL(-1)) and hydrogel freezing temperature (-196 degrees C). Low precursor concentration promote formation of more hydrophobic aerogels. All aerogels display tendencies for dispersive, dipole-type and electron donor interactions. Moreover, a repulsion of electron lone pairs was observed, as well as shape-based selectivity (originating from porosity and surface roughness) in gas-solid adsorption process. Analysis of the free surface energy revealed that the maximum value (193.21 mJ m(-2)) is obtained at 7.2 mg mL(-1) precursor concentration, -104 degrees C hydrogel freezing temperature and 23 h gelation time. Presented findings can translate directly into reduced graphene oxide aerogels tailored for specific applications such as adsorption or catalysis.

Automated summary

Efficient adjustment of reduced graphene oxide aerogels properties requires understanding of the relationship between experimental factors and aerogel properties. In this study, the effects of precursor concentration, gelation time, and hydrogel freezing temperature on the surface and textural functionalities of reduced graphene oxide aerogels were investigated with the use of gaseous organic probes and experimental design. The results showed that precursor concentration and hydrogel freezing temperature had the strongest influence on the textural properties, with a negative correlation with apparent surface area. The findings can be applied to tailor reduced graphene oxide aerogels for specific applications such as adsorption or catalysis.