▎ 摘　　要

NOVELTY - Preparing porous graphene film comprises (i) cutting polyimide film, using a fixing device to fix the film on a flat substrate, ensuring the film is flat, adjusting relative position of substrate and laser light source, focussing laser on film material surface, setting processing parameters and entering desired engraving pattern in laser control software and performing laser processing to obtain a laser-induced porous graphene film and (ii) performing oxygen plasma treatment on the laser-induced porous graphene film for 60-120 seconds to obtain a laser-induced porous graphene film. USE - The graphene film is useful in seawater desalination and evaporative humidifier device (all claimed). ADVANTAGE - The film: has porous structure, high light absorption rate; ensures good light-to-heat conversion ability; reflects incident sunlight multiple times; increases optical path and absorption rate of sunlight; and is hydrophilic and can fully contact with liquid water. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for porous graphene film prepared using above method.