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This paper utilized the hydrothermal method and freeze-drying technology to prepare the macroscopic aerogel structure and powder structure of MOF-808/RGO. Through comparative analysis of aspects such as photocatalytic CO 2 reduction performance, electron transfer efficiency, macroscopic structure, and microstructure, it has been discovered that aerogel structure can provide favorable conditions for mass transfer of CO 2 and water molecules, and light propagation. The introduction of RGO successfully captures electrons and the reduction reaction occurs on the surface of the material. [Display omitted] • Macroscopic aerogel and powder structures of the MOF-808/RGO composite photocatalysts were fabricated separately and used for comparison. • The photocatalytic performance of the MOF-808/RGO macroscopic aerogels in reducing CO 2 to CO was approximately 16 times that of MOF-808 and 12 times that of RGO. • The aerogel structure provides an abundance of pore structures within the material. • The presence of the aerogel structure successfully enhanced the photothermal and photoelectric conversion efficiencies of the composite photocatalysts. Three-dimensional (3D) macroscopic aerogels have emerged as a critical component in the realm of photocatalysis. Maximizing the integration of materials can result in enhanced efficiency and selectivity in photocatalytic processes. In this investigation, we fabricated MOF-808/reduced graphene oxide (RGO) 3D macroscopic aerogel composite materials employing the techniques of hydrothermal synthesis and freeze-drying. The results revealed that the macroscopic aerogel material exhibited the highest performance in CO 2 reduction to CO, particularly when the concentration of RGO was maintained at 5 mg mL−1. In addition, we synthesized powder materials of MR-5 composite photocatalysts and conducted a comparative analysis in terms of photocatalytic CO 2 reduction performance and electron transfer efficiency. The results show that the macroscopic aerogel material boasts a high specific surface area, an abundant internal pore structure, and increased active sites. These attributes collectively enhance light energy utilization, and electron transfer rates, thereby, improving photothermal and photoelectric conversion efficiencies. Furthermore, we conducted in-situ FT-IR measurements and found that the M/R-5 aerogel exhibited the best CO 2 adsorption capacity under a CO 2 flow rate of 10 mL min−1. The density functional theory results demonstrate the correlation between the formation pathway of the product and the charge transfer pathway. This study provides useful ideas for realizing photocatalytic CO 2 reduction of macroscopic aerogel materials in gas–solid reaction mode. [ABSTRACT FROM AUTHOR]