Artificial leaf for harnessing sunlight
doi:10.1038/nindia.2017.109 Published online 27 August 2017
Using a nanocomposite, researchers have made a thin-film device that can absorb sunlight like a natural leaf and split water, making it potentially useful for generating hydrogen fuel1.
Producing hydrogen by harnessing the Sun’s power depends on various factors such as light-absorbing efficiency, charge separation and migration in a photocatalyst. It is difficult to make such a versatile catalyst. Most catalysts can absorb only the ultraviolet rays of sunlight.
Scientists from the CSIR-National Chemical Laboratory, Pune, prepared a wireless photochemical cell by using a nanocomposite made of gold nanoparticles, titanium dioxide and specific quantum dots.
The cell was dipped in an aqueous solution and exposed to sunlight. A camera recorded showed instant generation of hydrogen bubbles. The cell exhibited a power conversion efficiency of 5.6% — much higher than a similar wired cell.
When exposed to sunlight for 25 hours, the wireless cell retained its efficiency without any light-induced corrosion. The wireless cell doesn’t need any external voltage and performs better than existing solar cells.
“In the future, such cells can be integrated with cars to generate and store hydrogen fuel,” says lead researcher Chinnakonda S. Gopinath.
1. Patra, K. K. et al. Possibly scalable solar hydrogen generation with quasi-artificial leaf approach. Sci. Rep.7, 6515 (2017)