"A UK-based team of researchers has created a graphene-based sieve capable of removing salt from seawater. The sought-after development could aid the millions of people without ready access to clean drinking water."
See salt water filter invented.
Speaking of graphene supercapacitors, see also: Kaner Laboratory researchers develop battery-like supercapacitor
Speaking of filters, I have been getting my refrigerator filters at discountfilters.com for years and am perfectly happy with them. This is not an "affiliate link."