Efficient water oxidation under visible light by tuning surface defects on ceria nanorods

Fluorite CeO2 nanorods (NRs) with tunable surface defects are successfully prepared via hydrothermal synthesis followed by post-calcination under different atmospheres. Impressively, the CeO2 NRs obtained under mixed Ar and H-2 gas at 800 degrees C exhibit superior catalytic activity towards water oxidation under visible light (lambda >= 420 nm), which is 10 times higher than that of CeO2 NRs treated under air at 800 degrees C. Detailed characterization and theoretical analysis reveal that the rich surface defects including surface oxygen vacancies and Ce3+ ions are the origin of the enhanced water oxidation performance of the CeO2 NRs treated under the reduced atmosphere.