HyperSolar harnesses sunlight

to produce clean hydrogen fuel

Image Credit: Wang R&D Group, UC San Diego Jacobs School of Engineering

source:gizmag.com/hypersolar-hydrogen-fuel | azocleantech.com

HyperSolar claims it is developing a zero carbon method of producing hydrogen gas from wastewater by harnessing solar energy

source: gizmag.com/hypersolar-hydrogen-fuel

Rapid hydrogen generation on the surface of nanotree electrodes

that are submersed in water and illuminated by simulated sun light.

Nanowires are made from silicon or zinc oxide

3D branched nanowire array

Using solar energy for water splitting is the hottest topic in hydrogen fuel

Wang’s team has mimicked this structure in their “3D branched nanowire array” which uses a process called photoelectrochemical water-splitting to produce hydrogen gas. Water splitting refers to the process of separating water into oxygen and hydrogen in order to extract hydrogen gas to be used as fuel. This process uses clean energy with no green-house gas by-product. By comparison, the current conventional way of producing hydrogen relies on electricity from fossil fuels [ comment: or solar PV electricity ]

Artificial photosynthesis

The vertical nanotree structure also improves the output of hydrogen gas by extracting very tiny hydrogen gas bubbles rapidly. In addition, the vertical branch structure has increased the surface area by at least 400,000 folds for chemical reactions.

The research team’s next step is artificial photosynthesis wherein sunlight is absorbed by plants, which also gather water and carbon dioxide from the surroundings to produce carbohydrates to drive their own growth. The team plans to imitate this process to harvest carbon dioxide from the surroundings in order to decrease carbon emissions and produce hydrogen fuel from it.

source: ucsd.edu search Wang Nanotrees

related:

ECE Prof. Deli Wang on ScienceLive: Solar Cells Go Nano

Find out how two new technologies (the first produces solar cells from plastics and other organic compounds; the second uses tiny inorganic nanoscale wires to capture the sun's energy) capture sunlight, how scientists use nanotechnology to create these cells, and how they can help solar panels churn out more power for less money ece.ucsd.edu/node/2687

Nanowires convert up to 15% of sunlight ?

(organic solar cells up to 10%)

The efficiency of nanowire solar cells have been increase dramatically in the past few years, from tenth of 1% to 15-16% vertical nanowire array cells from UC Berkeley recently, which is still lower than the best Si cells, but the improvement is fast advancing.

Nano Problems to solve: surface recombination and contact design

The main challenges of nanowire solar cells, which I think, are (i) managing the surface states of nanowires to reduce the surface recombination, including finding the right materials, and (ii) designing/fabricating devices allowing the effective carrier collection (for example, how to design/engineer the contacts, how to avoid current crowding in nanowires, etc.)

Durability of organic solar cells: 5 years

Good barrier films needed to exclude oxygen and water vapor for the cell

Organic solar cells in the market by 2020

2 Technologies: solar from plastic or organic compounds

Researchers are making rapid progress on two technologies that hope to do just that. The first produces solar cells from plastics and other organic compounds

source: news.sciencemag.org