Hydrogen from Sunlight

In the quest for an efficient and inexpensive way to produce hydrogen, scientists have developed a method that mimics photosynthesis to create the clean-burning gas.

All photocatalytic systems operate essentially the same way: light absorbing materials (known as chromophores) produce electrons when exposed to light, and a catalyst combines the electrons with protons from a solution to form hydrogen gas. The new method, however, differs from traditional processes in several key ways.

In a conventional system, the chromophores consist of organic molecules, which deteriorate after a few hours. The new setup uses cadmium selenide nanocrystals, which were still going strong after two weeks. Traditional systems also use platinum-based catalysts, whereas the new method uses nickel, which is more affordable and less toxic. The new process can also be tuned to capture energy from a broader light spectrum, making it more efficient.