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Flawed graphene structure makes fuel cells better

Flawed graphene structure actually improves fuel cells. A new study has found that the efficiency of fuel cells can be improved by introducing flaws into graphene used in these cells.

The researchers say that the honeycomb structure of atom-thick graphene allows having a number of tiny holes results in a proton-selective membrane paving the way for improved fuel cells.

It was not an easy task to separate protons from hydrogen for fuel cell technology but scientists from Northwestern University collaborated with researchers from five other institutions and found that slightly imperfect graphene can shuttle protons from one side of a graphene membrane to the other in just seconds.

The findings of the study were published in the journal Nature. The researchers said in the report that the selectivity and speed of the imperfect version are much improved over conventional membranes. It could give engineers a possible new and simpler model of fuel cell design.

"We found if you just dial the graphene back a little on perfection, you will get the membrane you want," says Franz J. Geiger, a Northwestern chemistry professor. "Everyone always strives to make really pristine graphene, but our data show if you want to get protons through, you need less perfect graphene."

In terms of atomic scale, protons are fairly big and it makes them difficult to be driven through a single layer of structurally perfect graphene at room temperature.

When graphene was immersed in water, the researchers observed that protons were moving through it. The researchers tried to understand the phenomenon by using computer simulations, imaging techniques and lasers.

The observation revealed that naturally occurring defects in the graphene triggers a chemical conveyor belt that took few seconds to shuttle protons from the water on one side of the membrane to the other.