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 reduction reaction (CO RR), the development of photocatalysts that suppress H evolution reaction (HER), during CO RR, remains still a challenge. Here, new insight is presented for controllable CO 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 RR activity was achieved by a surface decoration of the yolk@shell structure with Au (PET) clusters as favorable electron acceptors, resulting in longer charge separation in Au@CN/Au 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 /G Y@S structure displays high photocatalytic CO RR selectivity of 88%, where the CO and CH 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.