In a world where billions lack clean water, scientists have found a way to pull it from thin air.
An international team of researchers led by Nobel Laureate Professor Sir Kostya Novoselov and Professor Rakesh Joshi has developed a groundbreaking nanomaterial capable of harvesting clean drinking water from vapors in the atmosphere with unprecedented efficiency.
Light as a feather and supercharged with water-absorbing power, the material can soak up more than three times its weight in water, offering a scalable, low-energy solution to one of the planet’s most pressing challenges.
“Our technology will have application in any region where we have sufficient humidity but limited access to or availability of clean potable water,” Joshi said.
Bonded over water
Built from graphene oxide, a well-known, single-atom-thick carbon sheet laced with oxygen-containing groups, the new nanomaterial can attract water molecules, thanks to its surface chemistry.
Calcium also has strong water-adsorbing properties. To explore how the two materials might work together, the researchers intercalated calcium ions (Ca²⁺) into the graphene oxide structure.
Both calcium and graphene oxide independently form strong hydrogen bonds with water, a key factor in effective atmospheric adsorption.
But when combined, the interaction between calcium and oxygen altered the hydrogen bonding network, significantly strengthening the bonds and allowing the material to absorb much more water than either component could alone.
“We measured the amount of water adsorbed onto graphene oxide by itself and we measured X. We measured the amount of water adsorbed onto calcium itself and we got Y. When we measured the amount of water adsorbed onto the calcium-intercalated graphene oxide we got much more than X+Y. Or it is like 1+1 equals a number larger than 2,” said Xiaojun (Carlos) Ren, UNSW School of Materials Science and Engineering, and first author on the paper.
Thrice as absorbent
To boost the material’s water-absorbing power even further, the team shaped the calcium-intercalated graphene oxide into an aerogel, the lightest solid material full of microscopic pores.
This porous structure allowed the material to soak up water much faster than standard graphene oxide. It also gave the material sponge-like qualities, making it easier to release the absorbed water when gently heated.
“The only energy this system requires is the small amount needed to heat the system to about 50 degrees to release the water from the aerogel,” says Prof Daria Andreeva, a co-author of the paper.
The research also combined hands-on experiments with powerful computer simulations, supported by the Australian National Computational Infrastructure (NCI) supercomputer in Canberra.
“The modelled simulations done on the supercomputer explained the complex synergistic interactions at the molecular level, and these insights now help to design even better systems for atmospheric water generation, offering a sustainable solution to the growing challenge of fresh water availability in regional Australia and in water-stressed regions across the globe,” said Professor Amir Karton of the University of New England who led the computational effort.
While the discovery is still at a fundamental research stage, industry partners are already involved in efforts to scale up the technology and develop a working prototype for real-world testing.