Researchers in Australia has created a solar-powered paint capable of absorbing water vapour and splitting the water molecules into hydrogen and oxygen. Hydrogen is a very attractive fuel from an environmental perspective, because when it burns, the only emission is water.
“Our new development has a big range of advantages,” says lead researcher Torben Daeneke from RMIT University in Melbourne, Australia. “There’s no need for clean or filtered water to feed the system. Any place that has water vapour in the air, even remote areas far from water, can produce fuel.”
In a country such as Australia, there are large tracts of sun-drenched land that have moist in the air but few good sources of freshwater in the ground.
“This system can also be used in very dry but hot climates near oceans,” says Daenekes college Kourosh Kalantar-zadeh. “The sea water is evaporated by the hot sunlight and the vapour can then be absorbed to produce fuel. This is an extraordinary concept — making fuel from the sun and water vapour in the air.”
The new paint contains a newly developed compound: synthetic molybdenum-sulphide.
Synthetic molybdenum-sulphide acts like silica gel (which absorbs moisture very well) but is also a semi-conductor that catalyses the splitting of water molecules into atoms.
In order to get the paint to absorb sunlight, the researchers included titanium oxide, a pigment already used in many white wall paints.
“We found that mixing the compound with titanium oxide particles leads to a sunlight-absorbing paint that produces hydrogen fuel from solar energy and moist air,” says Daeneke. “Titanium oxide is the white pigment that is already commonly used in wall paint, meaning that the simple addition of the new material can convert a brick wall into energy harvesting and fuel production real estate.”
Watch the video
Read the paper
The research has been published as “Surface Water Dependent Properties of Sulfur Rich Molybdenum Sulphides – Electrolyteless Gas Phase Water Splitting” in ACS Nano, a journal of the American Chemical Society. The DOI is 10.1021/acsnano.7b01632
Torben Daeneke, Nripen Dahr, Paul Atkin, Rhiannon M. Clark, Christopher J. Harrison, Robert Brkljača, Naresh Pillai, Bao Yue Zhang, Ali Zavabeti, Samuel J. Ippolito, Kyle J. Berean, Jian Zhen Ou, Michael S. Strano, Kourosh Kalantar-zadeh. Surface Water Dependent Properties of Sulfur-Rich Molybdenum Sulfides: Electrolyteless Gas Phase Water Splitting. ACS Nano, 2017; DOI: 10.1021/acsnano.7b01632