Shape-Dependent CeO2@BiOI for Degradation of Aqueous Cr(VI)

CeO 2 with different morphologies (nanoparticles/NP, nanorods/NR, nanocubes/NC, nano-octahedra/NO) are synthesized and decorated on BiOI nanoplates substrates to form CeO 2 @BiOI composites, which are used for aqueous Cr(VI) degradation. The intersurface states between BiOI and diverse CeO 2 nanoparticles exhibit distinct behaviors when checked by XPS and photoluminescence intensity. The Cr(VI) degradation results show that the synthesized CeO 2 @BiOI nanocomposites possess higher photocatalytic activity than pure CeO 2 or BiOI, and the CeO 2 -NP@BiOI nanocomposite (molar ratio of CeO 2 : BiOI = 1:2) is the best one among them, with which the Cr(VI) is degraded up to 95.0% after 30 min irradiation using it as the photocatalyst. The superior catalytic performance of CeO 2 -NP@BiOI can be attributed to a higher Ce 3+ ratio of CeO 2 -NP, a larger specific surface area, relatively low OH/CO 3 2− content on the composite surface, and especially the good interaction between the CeO 2 (111) facet and the BiOI surface.