Fujitsu claims, the use some advanced materials is increasing the effeciency of production of oxygen in Artificial Photosynthesis using sunlight and water by nearly 100-fold.
To artificially produce storable energy in the form of hydrogen and organic compounds requires extraction of reaction electrons from a photocatalyst material using light source and electrode that help in efficiently reacting with water or CO2. Earlier, semiconductor materials and relatively coarse-grained photocatalyst materials have been used in low-density rigid structures for the photo reactive electrodes where sunlight and water react. But the issue with that was the usable wavelengths of light in sunlight (visible light) fall in a narrow range and was difficult to achieve sufficient current flow from the chemical reaction.
Fujitsu could change that by using a thin film technology. Fujitsu has improved the methods of forming thin films (nano particle deposition of electroceramics on flexible mounting sheets to create capacitors or other passive components). To develop a process technology for layering thin films on a substrate, Fujitsu' developers have used a nozzle to spray the photocatalyst-material particle that fragments the particle on a thin plate.
The key features Fujitsu explains are as follows:
1. Fujitsu could expand usable wavelength of sunlight so that sunlight is very well utilized for this purpose.
After creating a film of the raw-material photocatalyst-material particle, it is formed into a crystalline structure having deviation at the molecular level, which broadens the spectrum of sunlight that can be absorbed from a maximum wavelength of 490nm using existing technology to 630nm with this technology, more than doubling the usable sunlight that is captured.
2. The film what Fujitsu has used had a good crystalline structure lacking in macro- or micro-level flaws, and precisely formed structure with high electrical conductivity between the particles in the material. This enables electrons electrically excited by photons in sunlight to be efficiently transmitted to the electrodes.
3. A structure formed of nano-sized particles ensures a large surface area. Due to this new technique, Fujitsu can increase the surface area so that it can react with water could react with more surface area.
4. The crystalline surface for systematically structured to boosts electron density throughout the material's crystal structure.
This promoted higher interaction between water and sunlight.
Benefits include doubling the usable amount of light which is increased by light a factor of 50 the surface area of the material that can react with water. All together, given advantage where the research report confirm to increase the efficiency in producing electricity and oxygen by more than a factor of 100 claims Fujitsu.
Fujitsu is continuing its research to develop this technology further.