The “hydrogen economy” has been lauded as America’s energy future by everyone from President Bush to SUV drivers pumping $100 of gasoline into the tank. But hydrogen production remains a serious obstacle to fulfilling the promise of the water-based energy source that could eliminate pollution and the nation’s dependence on foreign oil. Hydrogen is currently obtained by splitting it from petroleum hydrocarbons or by using electricity to break water into hydrogen and oxygen. The first process still requires oil, while the second is costly and expends energy.

Dr. Paul Maggard thinks the answer to the hydrogen production problem just might be found in metal-oxide powders, some water, and a bit of sunshine. The assistant professor of chemistry in the College of Physical and Mathematical Sciences is working to synthesize metal-oxides to act as photocatalysts and break down water into hydrogen and oxygen. Several metal-oxides already produce such a reaction—scientists still aren’t quite sure of the molecular processes involved—but they tend to work only under ultraviolet light. Maggard, who says he’s “just always had an intense interest in solar energy,” wants to tweak them enough so they can work in the visible spectrum as well.

Because visible light contains less energy than ultraviolet rays, he is trying to shorten the band gap, or distance electrons have to travel in solids to become excited by light. Using funding from an Arnold & Mabel Beckman Foundation Young Investigators Award, Maggard is blending the metals in known photocatalysts like sodium tantalate with transition metals like cobalt and nickel to squeeze that band gap. That would make it easier for sunlight to get the electrons in the metal-oxide interacting with the water molecules, which then split into H? and O?. “It’s really a matter of energy distance,” he says. “I’m trying to shorten the energy gap the electrons have to cross before they can initiate the oxidation and reduction reactions.”

Mixing in those transition metals is Maggard’s immediate challenge. He would like to layer the molecules between those of the metal-oxide blocks and is using a molten salt flux to create particles of various sizes to test. At the same time, his research is uncovering more about the basic chemistry behind photocatalysts. “As we decrease the band gap size, there is less room for error,” he says. “We really need to understand the mechanism to be successful in the long term.”