3D printed porous nickel-cobalt oxide objects synthesized by interconnection and thermal conversion of metal hydroxide acrylate nanoparticles

Abstract

We report a cross-linker-free 3D printing strategy for fabricating hierarchically porous nickel-cobalt oxide objects using highly concentrated dispersions of metal hydroxide acrylate nanoparticles. By employing an optimized photoinitiator, millimetre-scale nanoparticle-based structures were successfully printed without the need for cross-linking agents. Upon thermal treatment under inert atmosphere, the printed objects transformed into Co–Ni alloy/carbon nanocomposites via intermediate carbide phases. Subsequent oxidation removed carbon domains and produced porous metal oxide architectures with tuneable meso- to macroporosity, while preserving the original printed shapes. This solid–solid phase separation process enabled pore formation without sacrificial templates or collapse of structure. Our approach offers a streamlined route to functional ceramic frameworks, with potential applications in catalysis, energy storage, and separations.