Authors: Wenchao Shangguan, Guoqiang Li, Shidi Gui, Xiaodong Zhang, Sugang Meng, Shifu Chen, Yingxuan Li
Published: 2025-03-23
Source: Full article
AbstractSeparating photoexcited holes in metallic nanostructure to drive H2O oxidation reaction to balance the CO2 photoreduction reaction is highly desirable, but challenging. The bottleneck lies in the sluggish kinetics of both photoexcited hole transfer and H2O oxidation. Herein, this work demonstrates that the in situ reconstruction of n‐type wide‐bandgap AlOOH‐supported Au nanoparticle heterogeneous photocatalyst, triggered by thermal and photothermal cooperative effect during photocatalytic reactions, facilitates the efficient CO2 photoreduction through optimizing the Au 5d‐band holes separation and H2O activation. In situ and ex situ characterizations evidence restructuring at interfaces to form an ultrathin γ‐Al2O3 nanolayer (≈2 nm thickness), which optimizes the energy band structure and promotes spontaneous transfer of photoexcited Au 5d‐band holes to the valence band of AlOOH, and prolongs the lifetime of electrons available for CO2 reduction on Au. Furthermore, hydroxyl vacancies generated during restructuring process are demonstrated to promote H2O adsorption and lower the energy barrier for O2 formation, supplying adequate protons for CO2 protonation reduction and thereby boosting CO2 photoreduction efficiency. This study offers valuable insights into the underlying mechanisms of utilizing n‐type semiconductors to separate photoexcited d‐band holes in metal nanoparticles.