What could be better than a solar cell that captures most of the visible light spectrum to generate energy? A cell that can capture the whole visible light spectrum and turn the energy into hydrogen. The cell is actually a molecule, and it is a busy molecule: it not only harnesses 50 percent more solar energy than existing solar cells, but it also turns this energy into hydrogen.
“The whole idea is that we can use photons from the sun and transform it into hydrogen. To put it simply, we are saving the energy from sunlight and storing it into chemical bonds so it can be used at a later time,” explains the lead researcher in the team that developed the molecule, chemistry professor Claudia Turro from the Ohio State University.
“What makes it work is that the system is able to put the molecule into an excited state, where it absorbs the photon and is able to store two electrons to make hydrogen,” Turro added. “This storing of two electrons in a single molecule derived from two photons, and using them together to make hydrogen, is unprecedented.”
The molecule is a form of rhodium—an inert metal and member of the platinum group—and because it can both collect solar energy and then act as a catalyst to turn it into hydrogen, it makes for a much more efficient fuel production system than existing alternatives, at least with respect to energy loss during the process of conversion of solar energy into hydrogen.