Method for making porous graphene membranes and membranes produced using the method

A method for making a porous graphene layer of a thickness of 4-11 nm with pores having an average characteristic width in the range of 1-1000 nm,

• comprising the following steps:
• providing a catalytically active substrate to catalyse the graphene formation under chemical vapour deposition conditions, said catalytically active substrate on its surface being provided with a plurality of catalytically inactive domains having a nanostructure essentially corresponding to the shape of the pores in the resultant porous graphene layer, wherein the catalytically active substrate is provided on its surface with the plurality of catalytically inactive domains by applying an essentially contiguous tungsten layer and by subsequently annealing at a pressure below normal pressure, to convert the tungsten film into the plurality of catalytically inactive domains;
• chemical vapour deposition using a carbon source in the gas phase and formation of the porous graphene layer on the surface of the catalytically active substrate, the pores in the porous graphene layer being formed in situ due to the presence of the catalytically inactive domains;
• wherein the catalytically active substrate is a copper-nickel alloy substrate with a copper content in the range of 98.6% by weight to 99.9% by weight and
• a nickel content in the range of 0.1% to 1.4% by weight,
• the copper and nickel contents complementing to 100% by weight of the catalytically active substrate, and
• wherein the porous graphene layer has an areal porosity in the range of 20% to 50%.