red cobalt

Water oxidation is essential for extracting hydrogen from H2O using sunlight. Back in 2010, Emory University researchers, led by Craig Hill, discovered a homogeneous catalyst for oxidizing water, which could lead to replicating photosynthesis, but more efficiently and in a controllable way. Emory chemists, funded by the U.S. Department of Energy, have written a new paper describing ways to use cobalt – a cheap and abundant element – to oxidize water.

The basic idea is photoelectrochemical water splitting (aka artificial photosynthesis), which combines a photovoltaic solar cell with electrolysis. The most efficient devices of this type use platinum – which is extremely expensive – to split the water. Using the Emory University research, the National Academies of Sciences released a paper in early June that described a device that integrates the cobalt catalyst with a silicon solar cell to split water.

The cobalt-based catalysts exhibit high levels of activity at room temperature and operate under neutral pH conditions. This means that this device doesn't have stability issues and, when combined with silicon, can increase the efficiency of photoelectrochemical water splitting.

Too complex? In simple terms, the cobalt-based catalyst, when paired with a silicon-based solar device, could be the breakthrough that leads to the production of cheaper hydrogen for use in fuel-cell vehicles. That's the idea, anyway.

[Source: Autopia | Image: jaja_1985 – C.C. License 2.0]