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IMAGE: TEM-Image of a α-SnWO4 film (green) coated with 20 nm NiOx (pink). At the interface of α-SnWO4 and NiOx an additional interfacial layer can be observed. view more
Credit: HZB
Hydrogen is an important factor in a sustainable energy system. The gas stores energy in chemical form and can be used in many ways: as a fuel, a feedstock for other fuels and chemicals or even to generate electricity in fuel cells. One solution to produce hydrogen in a climate-neutral way is the electrochemical splitting of water with the help of sunlight. This requires photoelectrodes that provide a photovoltage and photocurrent when exposed to light and at the same time do not corrode in water. Metal oxide compounds have promising prerequisites for this. For example, solar water splitting devices using bismuth vanadate (BiVO4) photoelectrodes achieve already today ~8 % solar-to-hydrogen efficiency, which is close to the material s theoretical maximum of 9 %.
unless you have storage which is the next phase of the energy revolution. in taming the sun, a fascinating new book that tackles these issues, the author reveals a startling statistic. if the united states turned off all of its sources of electricity immediately, it currently has enough storage capacity to power the country for just 43 minutes. so storage has a long way to go but many smart people have very big ideas for what to do about it. last year elon musk made the worth s largest lithium eye on battery from a sprawling wind farm in australia. resulting in outages in a fraction of second and store up to 129 mega watt hours of wind energy. that is still a drop in the bucket of country s demand but it s a start. here s another wild idea, solar fuels.