Nanofluidic membranes based on two-dimensional materials are promising materials for next-generation water desalination and purification. For instance, pristine and chemically modified graphene oxide membranes (GOMs) effectively block organic dyes and nanoparticles as small as 9 Å. However, these nanomembranes fail to exclude smaller inorganic salt ions, which would be required to extract pure potable water from unconventional water sources such as, salt water, industrial waste water, and rain water. With a novel approach called planar heterogeneous interface desalination researchers can now achieve a high salt rejection rate close to 97%.