OBTAINING HYDROGEN GAS
When we think of harnessing the sun for energy, we often think of solar power plants, which reflect sunlight to heat up steam in a turbine. So the question is, how do you provide power when the sun has already set or when weather conditions prevent normal operation of the plant?
One of the solutions being pondered is using solar power to create hydrogen gas. Not only is this easier to store than solar power itself, it also has higher energy density than any other fuel source. Now, engineers at the University of California Berkeley have developed a new material that could allow future solar fuel cells to more efficiently process water into hydrogen gas.
In their research, published in ACS Central Science, they were able to develop a metal-based material that can be used in solar fuel cells. The new material could split incoming water into steady streams of oxygen and hydrogen gas with sunlight.
DEVELOPING BETTER ANODES
Solar fuel cells form hydrogen by a process called solar electrolysis. During this process, one side of the cell acts as an anode and removes oxygen from the water while the cathode side produces the hydrogen gas.
The researchers were able to improve on previous fuel cells by developing a better anode for the process. While extensive research has been done on improving cathodes, most anode materials remain inefficient and prone to oxidation. Ultimately, they combined the properties of titanium oxide, which is able to perform electrolysis easily, with that of bismuth vanadate, which can absorb solar power easily.
The end result was a material that was far superior to either of the starting material.
Despite the improvement, Peidong Yang, the chemical engineer who led the team, believes that much more could be done to improve the anode. Even with the more efficient material, fuel cells remain wasteful and are still far from commercial viability.
Instead, Yang believes that his research could form a conceptual framework that would lead to future breakthroughs in anode materials. With more research, we might not that be far off from seeing hydrogen producing solar fuel cells soon.