Unexpected Discovery Brings Three Times More Solar Power

Sometimes, what we get is not what we expect – at all. For example, a team of scientists from Northeastern University and from NIST discovered by mistake how to produce more solar power by using the residue of a process used to build arrays of titania nanotubes. Now, physorg.com interprets this invention through the perspective of better hydrogen production, but improving the solar power capturing ability gives a lot more useful applications than only that of hydrogen production.

Titanium dioxide is used widely in foods, toothpastes and all other chemicals that need to be pigmented in white – even in donuts. 35 years ago, Akira Fujishima used titanium dioxide for the first time as a photocatalyst, producing hydrogen from water, electricity and sunlight. Since then, scientists have discovered how it can successfully be used in making more and more efficient dye-sensitized solar cells.

Northeastern University scientists used NISTS X-ray spectroscopy beamline at the National Synchrotron Light Source. The NIST facility uses low-energy x-rays that can be precisely tuned to specific elements to measure chemical bonds, and is at least 10 times more sensitive than commonly available laboratory instruments, allowing researchers to detect elements at extremely low concentrations. While making measurements of the carbon atoms, the team noticed spectroscopic data that indicated that the titania nanotubes had small amounts of potassium ions strongly bound to the surface, evidently left by the fabrication process that used potassium salts. This was the first time the potassium has ever been observed on titania nanotubes, previous measurements were not sensitive enough to detect it.

The team compared the performance of the potassium-bearing nanotubes to equivalent arrays prepared without using potassium, and got three times more energy from the potassium-enriched nanotubes. “The result was so exciting, that we got sidetracked from the carbon research,” says Latika Menon, from Northeastern.

Indeed, these nanotubes could be used to directly produce hydrogen by doing a direct light capture and electrolysis at the same time, but, as I said in the beginning, it could be used as an energy producer for any application. Really interesting.