context: Here, RGO serves as a 2D template and the carbon source to form the SiC/RGO nanocomposite by an in situ gas–solid reaction. The introduction of RGO not only reduces the recombination of photogenerated electron–hole pairs, but also promotes the transfer of photoexcited electrons between SiC and Li anode taking advantage of the high conductivity of RGO, which plays a crucial role in improving the performance of Li–CO2 batteries. The synthesis strategy of the SiC/RGO nanocomposite is displayed in Fig. 2a. By the sublimation of the solid Si at a high temperature, a new nucleus is generated on the surface of RGO by a gas–solid reaction (C(s) + Si(g) → SiC(s)), and then spreads around RGO to form a tightly connected SiC nanosheet on RGO. The morphology and the structure of RGO and SiC/RGO nanocomposite were studied by SEM and TEM. As shown in Fig. S1 (ESI†), the bare RGO exhibits a 2D nanosheet morphology. After the carbothermal process, SiC is uniformly distributed on the RGO substrate, presenting a distinct island-in-sea-like morphology (Fig. 2b and c). Furthermore, the elemental distribution of the material was studied by EDS. As shown in Fig. S2,† Si is present only in the island-like region and C exists throughout the test area, which directly proves that the island-like nanosheets observed in SEM and TEM images are SiC. The partial conversion of 2D RGO to the SiC/RGO nanocomposite facilitates the transfer of high energy electrons. The high resolution TEM (HRTEM) images (Fig. 2d) also demonstrate the tight junction between SiC and RGO. Clear lattice fringes with a d-spacing of 0.25 nm on the overlay correspond well to the (111) plane of SiC. It is also possible to distinguish between carbon layers due to the pleated RGO layer in the substrate with an interplanar distance of 0.34 nm. Apart from the enhanced electronic conductivity for the SiC/RGO composites, RGO also plays an important role in enhancing the CO2 adsorption capacity (Fig. S3†), which is beneficial for a higher actual discharge capacity of the cathode.