The invention relates in general to porous graphene-based films. In particular, the invention relates to a process for the preparation of a porous graphene-based films comprising reduced graphene oxide. The invention also relates to porous graphene-based films prepared by the process and to uses of such porous graphene-based films, in particular, in filtration applications. The invention further relates to porous multi-zone graphene-based films comprising different zones of different porosity.