Inherent superhydrophobicity of Sn/SnOx films prepared by surface self-passivation of electrodeposited porous dendritic Sn

Superhydrophobic Sn/SnOx (x = 1 and 2) films were facilely fabricated by surface self-passivation of three-dimensional (3D) hierarchical porous dendritic Sn while exposed to the air. The porous dendritic Sn was obtained rapidly by electrodeposition accompanying release of hydrogen bubbles. Influence of electrodeposition parameters on the surface morphology and wettabillity has been investigated in detail, including deposition potentials, deposition times and electrolyte concentrations. The maximum contact angle reached to 165° on the porous dendritic Sn/SnOx film electrodeposited in a solution of 60 mM SnCl2 and 1.5 M H2SO4 under −1.7 V for 20 s. Both the hierarchical micro-nanostructures and the spontaneously formed ultrathin surface passivation layer of Sn oxides endow the prepared Sn/SnOx surface with excellent inherent superhydrophobicity without further surface modification.