Sunlight Splits Water into Hydrogen and Oxygen: New Method for Clean Energy
Researchers have made a breakthrough when it comes to generating hydrogen. They've discovered a way to create hydrogen from water using sunlight, which may potentially result in a clean and renewable source of energy for the future.
Water-splitting experiments powered by sunlight have been tried since the 1970s. Yet this one is the first to use cobalt oxide and also the first to use neutral water under visible light at high energy conversion efficiency without co-catalysts or sacrificial chemicals. This, in particular, could pave the way for a future energy source.
So how did they do it? The researchers prepared the nanoparticles in two ways; they used femtosecond laser ablation and mechanical ball milling. More specifically, different sources of light were used, ranging from a laser to white light simulating the solar spectrum. Once the nanoparticles were added and the light applied, the water separated into hydrogen and oxygen almost immediately. In fact, twice as much hydrogen was produced as oxygen--as should be expected from the 2:1 ratio in water molecules.
The experiment has the potential as a source of renewable fuel. Yet there's still a ways to go. There's a solar-to-hydrogen efficiency rate at about five percent, which means the conversion rate is still too low to be commercially viable. A more feasible efficiency rate would be about 10 percent, meaning that 10 percent of the incident solar energy will be converted to hydrogen chemical energy by the process. In addition, researchers will have to reduce costs and extend the lifespan of cobalt oxide particles, which currently become deactivated after about an hour of reaction.
"It degrades quickly," said Bao in a news release.
Even so, the work represents a good point for further research. In the future, we may see a method that could create sustainable energy in an efficient, environmentally friendly and cost-effective way.
The findings are published in the journal Nature Nanotechnology.