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

Graphical In hot water : CeO 2 /A−Fe(OH) 3 composites synthesized by a secondary water bath at 100 °C exhibit superior photocatalytic activity. A−Fe(OH) 3 increases specific surface area, passivates the surface of CeO 2 , and reduces the activation energy of water oxidation. This work provides a new insight into exploring amorphous cocatalysts to enhance photocatalytic O 2 evolution activity and augment the possibility of overall water splitting based on CeO 2 . Noble-metal-free composites with good photocatalytic property are of great interest. Here, CeO 2 nanorods composites loaded with amorphous Fe(OH) 3 cocatalyst were designed and prepared via a secondary water bath at 100 °C. The as-synthesized CeO 2 /amorphous Fe(OH) 3 composites exhibited superior light photocatalytic activities compared to pure CeO 2 , 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 CeO 2 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 CeO 2 . 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 CeO 2 and amorphous Fe(OH) 3 cocatalyst accelerated the photogenerated charge separation efficiency and thus improved the photocatalytic performance of CeO 2 in photocatalytic water oxidation.