Researchers at Monash University in Melbourne have successfully developed the world’s most energy-efficient ‘artificial photosynthesis’ technique, which effectively mimics plant-based photosynthesis by using solar energy to convert water into hydrogen. The process, which creates hydrogen and oxygen by running an electric current through water, could be used to inexpensively power our homes and cars in just a few years, say the researchers.
Electrochemical splitting of water could provide a cheap, clean and renewable source of hydrogen as the ultimately sustainable fuel,” said Leone Spiccia, lead author of the research.
Success in the field of artificial photosynthesis normally means achieving an energy efficiency of above 10 percent. In this case the team’s system goes above and beyond, reaching 22.4 percent. While it’s not a particularly massive gain on the previous record – which stood at 18 percent – the Monash team was able to hit its result using nickel as a catalyst. This is significant because previous methods required using precious metals, whereas nickel is inexpensive, abundant, and offers great stability.
The team modified a much-researched and ubiquitous protein, Ferritin, which is present in almost all living organisms.
Ferritin’s usual role is to store iron, but the team removed the iron and replaced it with the abundant metal, manganese, to closely resemble the water splitting site in photosynthesis.
The protein also binds a haem group, which the researchers replaced with a light-sensitive pigment, Zinc Chlorin.
When they shone light onto the modified ferritin, there was a clear indication of charge transfer just like in natural photosynthesis.
Credit : http://www.anu.edu.au/