Nowadays, the decrease of CO2 concentration in the atmosphere and/or its utilization need urgent resolution. At the same time, preparation of advanced graphene-based composites through effective environmentally benign procedures remains in the focus of intensive research. In the present work, composites consisted of reduced graphene oxide and nanocarbons (rGO/nC) were prepared by simultaneous reduction reaction of solid graphite oxide and CO2 gas over alkaline earth reductant. The structure and the morphology of the prepared composite material were examined employing X-ray diffraction analysis and scanning electron microscopy. It was revealed that the characteristic narrow peak of the graphite oxide (GtO) at low 2θ (~11o) was not present in the pattern of the composite suggesting its successful reduction. Instead, a broad one positioned at 26o was recorded which was attributed to the formed nanocarbons. The observed accordion-like morphologies typical for reduced-graphene-oxide type of graphene evidenced the detachment of the graphene layers during the thermal treatment, while the formed nanocarbons were with irregular shape. The rGO/nC composite exhibited specific surface area (485 m2/g) higher than the pure nanocarbons (417 m2/g) obtained without addition of GtO. The outcome was attributed to the influence of the layered rGO which hinders the aggregation of the nanocarbons and facilitates their homogeneous distribution. The prepared composite can be considered as candidates for gas and energy storage applications, while the suggested environmentally benign preparation method can be scaled up to industrial extent due to simplicity.
