▎ 摘　　要

NOVELTY - Preparation of modified graphene film, involves (1) reducing the graphene oxide sheets to obtain graphene sheets, (2) using quaternary amine compounds to modify the graphene sheet obtained in step (1) to obtain a modified graphene sheet solution, (3) using a vacuum filtration device to filter the modified graphene sheet solution obtained in step (2) through a cellulose filter membrane, when there is no free water on the filter membrane, stopping the vacuum filtration to form a modified graphene membrane, and (4) placing the modified graphene film in a freeze dryer to solidify and dry the water molecules inside the modified graphene film. USE - Preparation of modified graphene film used in system for capturing carbon dioxide in air (all claimed). ADVANTAGE - The method ensures preparation of the modified graphene membrane material with the ability of adsorbing/desorbing carbon dioxide under different dry and wet conditions through synthesis and modification process, and the whole reaction process is simple and easy to control. The reaction raw materials are cheap and easy to obtain, and the production cost is low. The prepared modified graphene film has high selectivity, uniform skeleton pore size, high porosity and strong cycle stability, which can efficiently adsorb carbon dioxide in the air in a dry environment at room temperature and pressure. The adsorbed carbon dioxide can be desorbed by changing the environmental humidity, which has broad application prospects in the field of carbon dioxide capture.