Americans may be one step closer to driving zero-emission cars, as a new Lawrence Berkeley National Laboratory report published this month sheds light on new methods for harnessing solar energy.

Lab scientists have discovered a low-cost, zero-emission method of effectively utilizing the sun’s energy to extract hydrogen from water, according to a paper published Jan. 20 in Science Magazine’s website. This hydrogen could then be used for fuel cells.

“The idea is using the sun and water (for) generating hydrogen,” said Samuel Mao, career staff scientist at the lab and corresponding author of the paper. “Hydrogen would be used to fuel fuel cells, (and) fuel cells would be used to power cars.”

Mao’s report explains his work in using solar energy and the photocatalyst, titanium dioxide, to extract hydrogen from water. Lab scientists Xiaobo Chen, Lei Liu and Peter Yu co-authored the report with Mao.

Because solar energy alone is not enough to split water into hydrogen and oxygen, photocatalysts “do the work,” said Jin Zhang, a professor in the department of chemistry and biochemistry at UC Santa Cruz.

According to Mao, prior research has focused on adding materials to titanium dioxide to increase its solar absorption. Mao’s first proposal for solar hydrogen production was in 2004.

In his research, Mao applied high pressure and temperature to titanium dioxide, a common substance in white wall paint and sunscreen, to manipulate its atomic structure.

His recent report is the first to introduce the concept of atomic restructuring to aid in generating hydrogen, rather than simply adding materials to the photocatalyst.

Mao calls this atomic restructuring “disorder engineering,” which causes the white substance to change to black and enables it to absorb ultraviolet as well as visible and infrared light.

The more light it absorbs, the more hydrogen can be produced.

Mao said white titanium dioxide is not a very effective photocatalyst because it only absorbs ultraviolet light, which “accounts for less than 10 percent of the world’s solar energy.”

Zhang, who works on similar research on extracting hydrogen from water, described Mao’s research as “novel and significant” in an e-mail.

“This approach can (have) broad impact to … solar energy conversion,” he said in the e-mail.

This method of extracting hydrogen produces no greenhouse gas emissions or byproducts other than water, and then can be used for hydrogen fuel cells in vehicles and buildings.

The Fuel Cell and Hydrogen Energy Association is an advocacy organization for commercializing fuel cells and hydrogen energy.

Pete Barkey, the communications director for the association, said the research on hydrogen energy is “really encouraging” and fuel cells are “integral to the clean energy portfolio.”