Construction of Ce(OH)4 nanostructures from 1D to 3D by a mechanical force-driven method

Abstract

A simple protocol has been reported here to successfully perform a controllable conversion between Ce(OH)₄ nanorods [Ce(OH)₄-NR] and Ce(OH)₄ nanoflowers [Ce(OH)₄-NF] based on a prolonged mechanical force-driven stirring process. Results show that the Ce(OH)₄ nanostructures undergo a morphology transformation from the initial nanorods to irregular nanoflowers, then to nanoflowers emanating from one center only, by varying the stirring time before solvothermal reaction. The detailed study confirmed that the mechanical force significantly improved the mass transport of the solution and drove the seeds of Ce(OH)₄-NR [seeds-NR] to generate the seeds of Ce(OH)₄-NF [seeds-NF]. The final CeO₂ products (CeO₂ nanorods [CeO₂-NR] and CeO₂ nanoflowers [CeO₂-NF]) that inherited the original morphology were obtained by annealing Ce(OH)₄-NR and Ce(OH)₄-NF, respectively. To further optimize the performance of the final products, Au/CeO₂-NR and Au/CeO₂-NF were synthesized by a simple oxidation–reduction process, which led to increased surface areas and promising potential in CO oxidation.