Surface Plasmonic Resonance and Z-Scheme Charge Transport Synergy in Three-Dimensional Flower-like Ag–CeO₂–ZnO Heterostructures for Highly Improved Photocatalytic CO₂ Reduction

The design and engineering of plasmonic metal nanocomposite photocatalysts offer an operative approach for highly efficient CO 2 photoreduction. Herein, the authors report a plasmonic 3D flower-like (3DF) Ag–CeO 2 –ZnO nanocomposite catalyst with effective charge carrier separation/transfer and CO 2 adsorption capacity exhibiting a considerable enhanced performance compared to pure ZnO and CeO 2 for photocatalytic CO 2 reduction to CO and CH 4 under UV–vis light. The apparent quantum efficiency of the optimized sample is 4.47% at 420 nm, and the CO 2 to CO selectivity reaches up to ∼95%. The enhanced photocatalytic performance of 3DF Ag–CeO 2 –ZnO can be assigned to the prolonged absorption in the visible light region induced by the surface plasmon resonance (SPR) effect, the efficient separation of photogenerated charges, and the Z-scheme configuration. Furthermore, the photocatalyst displays excellent stability and reusability. The mechanism of the plasmon-mediated Z-scheme structure has been suggested in which Ag NPs act as both visible light absorber and electron mediator.