RMIT researchers have developed a solar paint that can absorb and split water vapour to generate the cleanest source of energy – hydrogen.
The paint is composed of a new compound called synthetic molybdenum-sulphide. This material acts like a silica gel – a substance that is commonly used in sachets to absorb moisture and keep food, medicines and electronics fresh and dry – but also as a s a semi-conductor, a property that allows it to split water atoms into hydrogen and oxygen.
RMIT lead researcher Dr Torben Daeneke said when mixed with titanium oxide particles, the compound turns into a sunlight-absorbing paint that produces hydrogen fuel from solar energy and moist air.
“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,” he said.
“Our new development has a big range of advantages. 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.”
Fellow researcher, Professor Kourosh Kalantar-zadeh, said hydrogen could also be used as an alternative to fossil fuels.
“This system can also be used in very dry but hot climates near oceans. The sea water is evaporated by the hot sunlight and the vapour can then be absorbed to produce fuel,” he explained
“This is an extraordinary concept – making fuel from the sun and water vapour in the air.”
Titled “Surface Water Dependent Properties of Sulfur Rich Molybdenum Sulphides – Electrolyteless Gas Phase Water Splitting”, the research has been published as in ACS Nano, a journal of the American Chemical Society.