Fabrication of Condensate Microdrop Self-Propelling Porous Films of Cerium Oxide Nanoparticles on Copper Surfaces

Condensate microdrop self‐propelling (CMDSP) surfaces have attracted intensive interest. However, it is still challenging to form metal‐based CMDSP surfaces. We design and fabricate a type of copper‐based CMDSP porous nanoparticle film. An electrodeposition method based on control over the preferential crystal growth of isotropic nanoparticles and synergistic utilization of tiny hydrogen bubbles as pore‐making templates is adopted for the in situ growth of cerium oxide porous nanoparticle films on copper surfaces. After characterizing their microscopic morphology, crystal structure and surface chemistry, we explore their CMDSP properties. The nanostructure can realize the efficient ejection of condensate microdrops with sizes below 50 μm. Water‐drop ejector seat: A facile, cheap, and scalable electrodeposition approach gives copper surfaces coated with porous films made of cerium oxide nanoparticles. The films have condensate microdrop self‐propelling (CMDSP) properties, that is, droplets move across and even jump from the surface (see time‐lapse photo). The key to the film preparation is the control over preferential growth of isotropic nanoparticles and the synergistic use of the hydrogen‐evolution reaction releasing tiny bubbles as pore‐making templates.