▎ 摘　　要

NOVELTY - Producing porous composite film comprise (a) preparing a porous polymer film; and (b) forming a graphene layer by irradiating a laser on one surface of the porous polymer film to carbonize an area of a predetermined thickness in the thickness direction of the polymer film. USE - The method is useful in producing porous composite film for solar-based vapor generating system (claimed). ADVANTAGE - The method uses less thermal/chemical energy compared to existing manufacturing method of similar materials; produces porous composite film in short period of time; and is economical. The porous composite film is fusion structure of hydrophilic polymer material and graphene having excellent heat dissipation and light heat properties, and can be used as functional solar water purification membrane. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) porous composite film having laser carbide graphene layer, prepared by the above method, where the graphene layer is formed in region of predetermined thickness in the thickness direction of the polyimide foam, and the light absorption rate is greater than or equal to 97% in the light wavelength of 250 to 2500 nm, and the water contact angle of the graphene layer is greater than or equal to 130 degrees , and the water contact angle of the polyimide foam itself is less than or equal to 80 degrees ; and (2) solar-based vapor generating system utilizing the photothermal properties of the porous composite membrane.