Facile fabrication of superhydrophobic Bi/Bi2O3 surfaces with hierarchical micro-nanostructures by electroless deposition or electrodeposition

Superhydrophobic metallic surfaces are attracting wide interest. In this work, two facile one-step methods (displacement reaction and electrodeposition) were developed to fabricate superhydrophobic Bi/Bi2O3 surfaces with hierarchical porous dendritic structures, where the Bi2O3 cover layer was formed by surface self-passivation of the deposited Bi. The influence of various experimental parameters on the surface morphology and wettability were investigated in detail, including concentration of solutions, deposition times, and deposition potentials. A maximum contact angle about 164° can be obtained on the fabricated superhydrophobic Bi/Bi2O3 surfaces by these two methods under optimized conditions without additional surface modification.