▎ 摘　　要

NOVELTY - The method involves generation of a contiguous, essentially non-porous membrane (5) with one or up to four graphene layers (4). The distributed point wise defect creation in the non-porous membrane with one or up to four graphene layers by way of irradiation (6). The generation and successive growth of the pores (3) at the defects generated in step by thermal annealing in the gas phase. The nano-porous membrane (1) consists of one single or a stack of two or three single graphene layers, optionally on a porous carrier layer, preferably a porous polymeric carrier layer. USE - Method for producing nano-porous membrane with one or up to four graphene layers, pores in membrane (claimed). ADVANTAGE - The double layer graphene (DLG) is used instead of single layer graphene (SLG) increases transfer yield of the membranes and additionally reduces possible leakage pathways through intrinsic defects within the graphene. The short etching times of 15 min enables angstrom-scale control over pore size leading to permeance increases of small gases by up to one order of magnitude, while maintaining or increasing the membrane selectivity towards gases with larger kinetic diameter. The selective etching conditions enable fabrication of highly porous graphene membranes with independent control of pore density and size with a dry and scalable process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a nano-porous membrane. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a protocol for gas separation graphene membrane fabrication. Nano-porous membrane (1) Pores (3) Graphene layers (4) Non-porous membrane (5) Irradiation (6)