Ce³⁺-Driven Rapid Surface Reconstruction Strategy for Nano-engineered Superhydrophobic Ultrathin Copper Foil

Cu is extensively used across various fields due to its excellent electrical conductivity, thermal conductivity, and machinability. However, it is prone to corrosion and biofouling in humid and contaminated environments, limiting its performance and durability. Herein, we report a Ce³⁺-driven electrooxidation method to construct uniform and dense Cu-Ce-O nanorods on ultrathin Cu foil (∼8.7 μm), achieving superhydrophobicity after subsequent fluorination. The incorporation of Ce salts into the electrolyte enables the controllable and rapidly oriented growth of nanorod structures. Density functional theory calculations revealed the selective adsorption mechanism of rare-earth Ce on different Cu₂O crystal planes, promoting preferential growth along the (110) plane and forming uniform nanorod arrays. This method avoids damage and overetching to ultrathin copper substrates from harsh acidic/basic environments and allows electrolyte recycling for over 10 cycles. The resulting superhydrophobic Cu exhibits self-cleaning, antialgae adhesion, enhanced corrosion resistance (η > 90%), and thermal stability up to 180°. This strategy provides insights into the construction of superhydrophobic ultrathin Cu foil and expands the prospects of rare earth salts in the metal surface and interface engineering.