Amorphous Fe(OH)₃ Passivating CeO₂ Nanorods: A Noble-Metal-Free Photocatalyst for Water Oxidation

Noble-metal-free composites with good photocatalytic property are of great interest. Here, CeO₂ nanorods composites loaded with amorphous Fe(OH)₃ cocatalyst were designed and prepared via a secondary water bath at 100 °C. The as-synthesized CeO₂ /amorphous Fe(OH)₃ composites exhibited superior light photocatalytic activities compared to pure CeO₂ , especially the sample with a loading time of 60 min. The photocatalytic oxygen generation rate could reach to 357.2 μmol h^-1  g^-1 , and the average apparent quantum yield (AQY) was 24.67 %, which was a 5.5-fold increase compared to the CeO₂ sample. The improvement of photocatalytic performance could be ascribed to three main reasons: First, loading the amorphous Fe(OH)₃ enlarged the specific surface area and passivated the surface of the pristine CeO₂ . Second, the amorphous Fe(OH)₃ ,which acted as a cocatalyst, provided many active sites, and reduced the reaction activation energy. Thirdly, the maximum interface with intimate contact between CeO₂ and amorphous Fe(OH)₃ cocatalyst accelerated the photogenerated charge separation efficiency and thus improved the photocatalytic performance of CeO₂ in photocatalytic water oxidation.