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.