Polydopamine thin film-assisted patterned chemical bath deposition of ZnO nanorods on arbitrary substrates

Abstract

Patterned nanostructures tethered on various substrates are of essential importance for both fundamental research and practical application but often require tedious and expensive fabrication procedures. We herein report a versatile and simple strategy to grow patterned zinc oxide (ZnO) nanorods by chemical bath deposition (CBD) on arbitrary substrates. This strategy relies on the inhibitory effect of the polydopamine (PDA) film on the CBD of ZnO nanorods on Fe³⁺ ion-activated surfaces. By patterning the adhesive PDA film via transfer-printing or UV photo-oxidation, patterned ZnO nanorods were well grown on various substrates including glass, silicon and plastic plates. The inhibition mechanism was investigated and found to be tightly associated with the unique metal coordination properties of the PDA film. This work demonstrates a versatile yet simple strategy to achieve patterned growth of ZnO nanostructures, discloses a new interplay between PDA and metal ions, and may shed light on the growth regulation of other inorganic nanostructures.