Abstract
Ultrafine cuprous oxide U-Cu2O (< 3 nm) was obtained via in situ reduction of Cu-based layered trimetal hydroxide on the polymeric carbon nitride (PCN). This facilely synthetic strategy with confinement effect results in a series of Z-scheme heterostructures U-Cu2O-LTH@PCN-X (X = 1, 2, 3,4, 6 and 15) via loading different amounts of PCN, which can promote CO2 photoreduction in water vapor with excellent stability. The CH3OH yield can reach to 440.78 μmol g~(-1), much superior to that of most Cu2O-based photocatalysts. Systematic investigations demonstrate that ultrafine nanoclusters and Z-scheme heterojunction can accelerate photogenerated carrier separation and extract holes to mitigate the degradation of U-Cu2O in U-Cu2O-LTH@PCN. The resulting U-Cu2O-LTH@PCN only presents < 4% loss of the activity after 5 recycle experiments, whereas bare Cu2O degrades completely within three cycles. This work supplies a new insight to improve the stability of U-Cu2O via extracting holes to achieve high-performance CO2 photoreduction.