Researchers discovered a catalyst capable of quickly creating hydrogen from sunlight. Published in the journal Nature Nanotechnology, the finding could lead the way to a clean and renewable source of energy, according to those behind it.
Scientists have been exploring ways to split water using light since the 1970s. The latest is unique for a number of reasons, however, including its use of cobalt oxide nanoparticles.
Jiming Bao, lead author of the paper and assistant professor at the University of Houston's Department of Electrical and Computer Engineering, said the study demonstrates nanotechnology's role in engineering a material's property.
The scientists prepared the nanoparticles in two ways, first using femtosecond laser ablation and the second through mechanical ball milling, both of which worked just as well, Bao said.
The light sources used ranged from a laser to white light simulating the solar spectrum, though the scientist noted that the experiment would likely be equally successful with natural light.
The researchers needed only to add nanoparticles and light for the water to separate into hydrogen and oxygen almost instantaneously, producing twice as much hydrogen than oxygen as would be expected based on the hydrogen's 2:1 ratio to water in H20 molecules.
Still, there's a catch. With a solar-to-hydrogen efficiency rate of roughly 5 percent, the conversion rate is too low for commercial viability. Bao said this number would have to double to about 10 percent first, meaning 10 percent of the incident solar energy would have to be converted to hydrogen chemical energy for the process to take off.
Another problem that needs fixing is finding a way to extend the lifespan of the cobalt oxide.
"It degrades too quickly," Bao said, noting the nanoparticles deactivated afer about an hour of reaction.
Researchers from Sam Houston State University, the Chinese Academy of Sciences, Texas State University, Carl Zeiss Microscopy LLC and Sichuan University all participated in the study.