Advanced Catalyst for CO 2  Photo-Reduction: From Controllable Product Selectivity by Architecture Engineering to Improving Charge Transfer Using Stabilized Au Clusters.

Despite enormous progress and improvement in photocatalytic CO 2 reduction reaction (CO 2 RR), the development of photocatalysts that suppress H 2 evolution reaction (HER), during CO 2 RR, remains still a challenge. Here, new insight is presented for controllable CO 2 RR selectivity by tuning the architecture of the photocatalyst. Au/carbon nitride with planar structure (p Au/CN) showed high activity for HER with 87% selectivity. In contrast, the same composition with a yolk@shell structure (Y@S Au@CN) exhibited high selectivity of carbon products by suppressing the HER to 26% under visible light irradiation. Further improvement for CO 2 RR activity was achieved by a surface decoration of the yolk@shell structure with Au 25 (PET) 18 clusters as favorable electron acceptors, resulting in longer charge separation in Au@CN/Au c Y@S structure. Finally, by covering the structure with graphene layers, the designed catalyst maintained high photostability during light illumination and showed high photocatalytic efficiency. The optimized Au@CN/Au c /G Y@S structure displays high photocatalytic CO 2 RR selectivity of 88%, where the CO and CH 4 generations during 8 h are 494 and 198 µmol/gcat., respectively. This approach combining architecture engineering and composition modification provides a new strategy with improved activity and controllable selectivity toward targeting applications in energy conversion catalysis.