▎ 摘　　要

NOVELTY - Forming an ultrathin graphene oxide membrane, comprises: dispersing a single-layered graphene oxide powder in deionized water to form a single-layered graphene oxide dispersion; centrifuging the graphene oxide dispersion to remove aggregated graphene oxide material from the single-layered graphene oxide dispersion; diluting the single-layered graphene oxide dispersion by greater than or equal to 10 times through addition of deionized water to the graphene oxide dispersion; and passing the single-layered graphene oxide dispersion through a substrate so that a graphene oxide membrane is formed on the substrate. USE - The method is useful for forming an ultrathin graphene oxide membrane which is useful: in a filtration membrane (all claimed) for separating hydrogen mixtures; as gas sensors; and for seawater desalination. ADVANTAGE - The method provides ultrathin graphene oxide membranes which: exhibit superior separation performance for hydrogen mixtures; and have great potential to realize high flux, and high selectivity gas mixture separation at low energy cost. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a filtration membrane, comprising a graphene oxide membrane having a thickness of 1.8-180 nm, where the graphene oxide membrane comprises 3-30 layers of graphene oxide flakes.