This solar-cell device mimics the ability of a leaf to convert sunlight into usable energy. It’s the brainchild of a team led by MIT’s Daniel G. Nocera, working in conjunction with researchers at SunCatalytix, a company Nocera founded.
The device is based on two water-splitting photocatalysts developed by Nocera’s group. Simply dropping the solar cell in water and exposing it to light, O2 bubbles begin streaming off the side coated with a cobalt borate catalyst, and H2 bubbles begin streaming off the other side coated by a nickel-molybdenum-zinc alloy catalyst. If placed in a vessel with a barrier, the H2 and O2 could be collected separately and stored, and then later be used to power a fuel cell. Nocera envisions this type of simple, low-cost solar cell, once optimized, could be useful to power individual homes in developing regions around the world.