Hierarchically nanostructured CeO2 films with superhydrophilicity and corrosion resistance by coupling of surface topography and oxygen vacancies

Functional superhydrophilic materials have attracted increasing attention because of their potential applications such as antifogging and heat transfer/dissipation. In this study, without UV exposure or any chemical modification, a type of CeO2 films with superhydrophilicity and excellent corrosion resistance have been successfully fabricated by a simple and effective one-step electrodeposition method. It is found that hierarchically nanostructured CeO2 films consisting of islands plus microcracks provide the fast channel for water spreading based on capillary effect, while numerous surface active sites originating from oxygen vacancies improve the interfacial affinity for water molecules, together resulting in the superhydrophilicity of CeO2 surface. Based on the consistent surface morphology and work function before and after corrosion in NaCl solution, such superhydrophilic CeO2 films exhibit excellent corrosion resistance. These results will be significant to understand and design superhydrophilic materials as well as explore their potential engineering applications.