Laser ablation processing of zinc sheets in hydrogen peroxide solution for preparing hydrophobic microstructured surfaces

• Laser ablation of zinc sheets was performed in hydrogen peroxide aqueous solution.
• ZnO and Zn(OH)2 were formed by nanosecond (ns) or femtosecond (fs) laser ablation.
• Flower-like structures composed of nanoneedles occurred on ns laser-ablated sample.
• The surface of ns laser-ablated sample exhibited superhydrophobicity.
• Fs laser-ablated sample surface had flaky nanostructures and high hydrophobicity.

Hydrophobic microstructured surfaces were prepared by nanosecond (ns) and femtosecond (fs) laser ablation of zinc sheets in hydrogen peroxide aqueous solution. It was found that ZnO and Zn(OH)2 were generated after ns or fs laser ablation. The ns laser-ablated sample, on which clustered flower-like microstructures composed of nanoneedles occurred, exhibited superhydrophobicity with a water contact angle (WCA) of 158.5° and a water sliding angle (WSA) of 4.3°. In contrast, the fs laser-ablated sample, which was covered with non-directional flaky nanostructures, showed high hydrophobicity with a WCA of 145.7° and a WSA of 12.5°. The one-step method proposed here may be useful for fabricating self-cleaning functional surfaces and devices.