Controlled synthesis of CeVO4 hierarchical hollow microspheres with tunable hollowness and their efficient photocatalytic activity

Abstract

Well-dispersed hollow CeVO₄ microspheres with tunable hollowness and porosity have been synthesized via a simple hydrothermal method using L-aspartic acid (L-Asp) as the capping agent. The products were characterized by XRD, SEM, TEM and DRS. The XRD results showed that the as-prepared samples were tetragonal phase CeVO₄ with high crystallinity. SEM and TEM observations indicated that the hierarchical hollow microspheres with different hollowness were constructed from nanoparticles, cubes or nanoflakes. N₂ adsorption–desorption measurements revealed that the BET specific surface area of the typical CeVO₄ hollow microspheres was up to 106.54 m² g⁻¹. During the synthesis, the amount of L-Asp and the reaction time were found to play important roles in determining the growth process and final morphologies of the CeVO₄ products. Time-dependent experiments clearly revealed that the CeVO₄ hierarchical hollow microspheres were governed by the self-assembly and Ostwald ripening process. Rhodamine B (RhB) was used as the dye pollutant for evaluating the photocatalytic properties of the products under UV radiation. The CeVO₄ hierarchical hollow microspheres exhibited excellent photocatalytic activity and good stability even after five repeated cycles of use, indicating that the CeVO₄ hierarchical hollow microspheres can be good candidates for photocatalytic degradation of organic pollutants.