Site-Selective Growth of Crystalline Ceria with Oxygen Vacancies on Gold Nanocrystals for Near-Infrared Nitrogen Photofixation

Site-selective growth of crystalline semiconductors on gold nanocrystals remains a great challenge because of the difficult control of both nucleation and growth dynamics as well as the easy agglomeration and deformation of gold nanocrystals at high temperatures of 400-1000 °C. Here we report a facile wet-chemistry route for the selective growth of crystalline ceria at the ends of gold nanorods (Au NRs) in the presence of a small amount of bifunctional K₂PtCl₄. Due to the smaller steric hindrance at the ends than at the side surface, K₂PtCl₄ may preferentially adsorb at the ends of Au NRs, triggering the autoredox reaction with the ceria precursor to obtain crystalline CeO₂ at the ends. Notably, the surface of grown ceria is rich in oxygen vacancies (OVs) that facilitate the adsorption and activation of N₂ molecules. The unique structure, the plasmon-induced hot carriers and the OVs make the obtained Au/end-CeO₂ an excellent catalyst for nitrogen photofixation under near-infrared (NIR) illumination.