▎ 摘　　要

In this paper, a Z-scheme nanosheet/porous nanosphere (NSP) heterojunction system composed of g-C3N4 (CN) and ZnO anchored on 3D graphene aerogels (GAs) was synthesized using a facile process. According to the results, the CN/ZnO/GA-7 showed a remarkable CO production rate of 33.87 mu mol.g(-1) under visible light irradiation, 25, 21 and 3 times higher than those of ZnO, g-C3N4, and CN/ZnO, respectively. Furthermore, this rate far exceeded the reported conventional photocatalytic reduction efficiency of CO2 . Moreover, the CN/ZnO/GA exhibited exceptional stability and potential for commercial applications. These NSP heterojunctions provided a strong interfacial interaction and brought about abundant active sites and coupling large interfaces. The unique structure promoted the transport and separation of photogenerated carriers and facilitated effective mass transport and light absorption. Additionally, a multi-electron series reduction mechanism based on Z-scheme photocatalytic system was proposed to explain the CO2 reduction over this material. Taken together, this work demonstrated a promising photocatalytic hybrid system with 3D aerogel-based Z-scheme NSP heterojunctions for efficient and stable CO2 reduction. (C) 2022 Published by Elsevier B.V.