Graphene has been used to turn seawater into clean drinking water.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/graphene-sieve-turns-seawater-clean-drinking-water-%E2%80%93-and-technology-can-be-scaled
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/international-business-times
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/science-and-technology
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drinking-water
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-quality
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/scientists