Metal-based underwater biomimetic gas film drag-reducing surface and preparation method and application thereof

The invention discloses a metal-based underwater biomimetic gas film drag-reducing surface and a preparation method and application thereof. The metal-based underwater biomimetic gas film drag-reducing surface comprises a metallic matrix, and further comprises a pit-like microstructure disposed on the surface of the metallic matrix and a zinc oxide nanorod array disposed on the surface of the pit-like microstructure. The metal-based underwater biomimetic gas film drag-reducing surface is inspired by the gas attached functional surfaces of water spiders, a laser etching technique is firstly utilized to process a micron-scale array structure with a pit-like shape on the surface of metallic matrix, a layer of zinc oxide seed crystal layer is deposited on the surface of the microstructure by adeposition process, finally, the zinc oxide nanorod array structure is grown on the surface of the microstructure by a hydrothermal method, and after heat treatment, a microstructure surface similarto that embedded with a br