Facile synthesis of CeO2 hollow structures with controllable morphology by template-engaged etching of Cu2O and their visible light photocatalytic performance

The novel ceria (CeO 2 ) hollow structures with uniform cubic, polyhedral and sphere shapes were successfully synthesized by template-engaged coordinating etching of shape-controlled Cu 2 O crystals. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microcopy (TEM), high resolution of transmission electron microcopy (HRTEM), X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR) and photoluminescence spectroscopy (PL). The photocatalytic oxygen evolution via water oxidation was investigated for CeO 2 hollow structures with varied shapes under visible light irradiation. The photocatalytic results indicate that polyhedral CeO 2 nanocages show the highest photocatalytic activity, in contrast with spherical CeO 2 hollow structure and cubic CeO 2 hollow structure. The excellent catalytic activity can be attributed to the unique properties of the polyhedral CeO 2 nanocages, including efficient light refection through the inner shells, more active sites for enhancing separation efficiency of charge carriers. It is expected that this study could provide helpful results for designing and exploration of novel hollow structures with tunable photocatalytic performance.