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.