Energy

Solar Paint Could Be a Big Step in the Race to Replace Carbon-Based Fuels

Researchers in Australia have developed a paint for roofs and other surfaces that turns moisture in the air into hydrogen, a sustainable form of energy.

Now researchers in Australia claim to have produced hydrogen using energy from the sun and moisture from the air in a cheap and easy process that entails painting a red wine-colored chemical compound on roofs and other surfaces.

“Hydrogen is the ideal energy on the planet,” said study co-author Kourosh Kalantar-zadeh, an engineering professor at RMIT University in Melbourne. “If you can turn water into hydrogen, you have an infinite source of energy.”

Described in a paper published today in the journal ACS Nano, the paint uses sunlight to break humidity down into hydrogen and oxygen, replacing electrolysis, the current cumbersome industrial method of passing an electric current through water to generate hydrogen.

Electric car entrepreneur Elon Musk and others have also blasted electrolysis for requiring too much carbon-based energy to merit pursuing hydrogen as a sustainable fuel. They’ve also said building hydrogen stations would take too much time and money to be worth the investment. 

But the study’s authors said their findings could have a big impact on the race to replace carbon-based fuels.

Hydrogen has numerous commercial applications now, including compressing it into a fuel for rockets and automobiles. (NASA is now the biggest user of hydrogen as a fuel, according to the Energy Information Administration.) Hydrogen also stores energy well, meaning it could become a component in sustainable fuel cells.

“Lithium ion batteries are the worst in terms of their carbon footprint,” said Torben Daeneke, a research fellow at RMIT University. “They have to be improved a lot to bring their carbon footprints down.”

The special paint is a mixture of molybdenum sulfide — a common lubricant — and nanoparticles of titanium dioxide, a substance that gives toothpaste and sunscreen their chalky white color. The researchers used a silicone membrane they invented in previous work that separates hydrogen from other gases, creating a system to draw off and bottle the gas.

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The process depends on solar energy, the researchers stressed. But Kalantar-zadeh believes it could someday upend the solar industry. The study authors have not patented their research, he said, because they wanted as many people as possible to investigate uses for the paint.

“We are talking about going from a photovoltaic economy to a hydrogen economy,” said Kalantar-zadeh. “It’s something you don’t want to restrict.”

RMIT University and the Australian Research Council funded the study.

The researchers didn’t know if they could change the reddish color of the mixture, but said they would tweak the compound in the future with the aim of maximizing the efficiency of hydrogen production or improving the membrane to better collect the gas.

In the meantime, the beauty of the findings was that the paint could produce a closed system to generate energy, Kalantar-zadeh said. Burning hydrogen produces water, after all.

“The water can go back into the system and produce more hydrogen from the sun,” he said.

WATCH: Where Does Hydrogen Come From?