[The following is an exact transcript of this podcast.]
Solar panels typically convert sunlight into electricity or heat. But photosynthetic vegetation converts sunlight into chemical energy. Now M.I.T.’s Daniel Nocera wants to bring photosynthesis to your home. Solar power only works, obviously, when the sun shines. Nocera’s idea is to take solar power and use it to for electrolysis—to break apart water into hydrogen and oxygen—which then could be recombined when needed in a fuel cell. The problem is that current electrolyzer technology takes a lot of energy in a harsh, alkaline environment. That’s because, surprisingly enough, it’s hard to get the oxygen out of the water, not the hydrogen.
Nocera designed a new catalyst for that oxygen step that works at room temperature and pressure, in a glass of water. When a current runs through an electrode, phosphate and cobalt in the water form a thin film on that electrode. And O2 bubbles right up. The work appears in the July 31st issue of the journal Science. This system could be paired with another electrode for the hydrogen side. Nocera believes that electrolyzers could be cheap and efficient within a few years.