▎ 摘　　要

NOVELTY - Preparing a porous graphene film, comprises: mixing graphene oxide and a solvent to form a mixture; applying the mixture to at least one surface of a substrate; and cooling the surface of the substrate to form water droplets on the surface, where the water droplets depress into the mixture on the substrate to form pores on the surface of the substrate. USE - The method is useful for preparing a porous graphene film, which is useful: in a device which is an electronic device or a membrane, where the electronic device is a field-effect transistor, an ultrasensitive sensor, an electrode, a capacitor or a battery, and the membrane is an air-tight membrane; and as an electrode which is a graphene electrode for battery application (all claimed), or a transparent conducting electrode. ADVANTAGE - The method: is simple, cost effective and scalable; and have shorter fabrication time and reduced fabrication cost.