AFFORDABLE storage of solar power has come a step closer. Electricity generated by solar panels during the day could split water into oxygen and hydrogen, which are then used to power fuel cells at night.
Normally electrolysis is used to split water, but this is costly. Now Daniel Nocera at the Massachusetts Institute of Technology has built a cheaper device by depositing cobalt and phosphate onto an indium tin oxide electrode. These chemicals catalyse the water-splitting reaction, so less electricity is needed to produce the same amount of oxygen.
The hydrogen stays in solution as positive ions until a second…
