Science has relentlessly sought nature’s ability to turn
sunlight into useful fuel. Recently, Penn State University
researchers developed a device that could split water and
produce recoverable hydrogen. “This is a proof-of-concept system
that is very inefficient. But ultimately, catalytic systems with
10 to 15 percent solar conversion efficiency might be
achievable,” said Thomas E. Mallouk, professor of materials,
chemistry and physics at Penn State. If the system could be
realized, it would provide a clean source of hydrogen fuel from
water and sunlight. Although solar cells can already produce
electricity from visible light at efficiencies greater than 10
percent, solar hydrogen cells are theoretically better light
absorbers because they can use more of the visible spectrum in a
process much like natural photosynthesis. Mallouk and W. Justin
Youngblood, a postdoctoral fellow in chemistry, together with
collaborators at Arizona State University, developed a catalyst
system that, combined with a dye, can mim