The photocatalytic capabilities of La2O3 incorporated in CeO2 for the removal of Pb(II) ions in water are reported in this work. La2O3-modified CeO2 particles are prepared by a solid-state reaction method at calcination temperature of 1000 degrees C and 1400 degrees C. The x-ray diffraction result demonstrates a solid solution Ce0.9La0.1O1.95 phase coexisting with the CeO2 matrix phase (Ce0.9La0.1O1.95-CeO2) obtained at a calcination of 1400 degrees C, while the mixed La2O3/La(OH)(3)-CeO2 phase is obtained at 1000 degrees C. The UV-photocatalytic activity for Pb(II) ion removal of the La2O3-modified CeO2 particles is significantly higher than that of pure CeO2. Ce0.9La0.1O1.95-CeO2 particles show stronger visible light absorption capacity and higher ability of photoelectrodeposition for the Pb(II) ion removal than the mixed La2O3/La(OH)(3)-CeO2 particles and pure CeO2. The high photocatalytic activity is supported by a strong photoluminescence signal from the Ce0.9La0.1O1.95-CeO2 particles, suggesting a high efficiency of photogenerated charge separation. A formation of p-type Ce0.9La0.1O1.95 and n-type CeO2 heterojunctions in Ce0.9La0.1O1.95-CeO2 particles also promote photogenerated charge transfer and efficiency restraining recombination of the charges.