Abstract: A method for the desalination of water, the method comprising flowing salt water through a free-standing single-layer membrane of nanoporous graphene having a first planar side that makes contact with the salt water and an opposing second planar side from which desalinated water exits, wherein said membrane contains nanopores having a size of up to 1 nm, along with a substantial absence of pores above 1 nm in size, wherein said nanopores up to 1 nm in size have pore edges passivated with silicon, wherein salt ions in said salt water are blocked from passing through said membrane while water in said salt water passes through said membrane to result in desalinated water exiting said membrane.