Graphene holds a lot of promises. The lightweight, atom-thin sheet of carbon with a honeycomb structure is stronger than steel, and far more conductive than copper. Scientists are still struggling to create perfect sheets of graphene for such applications. But a new study reveals that even ‘defective’ graphene could be extremely useful in certain situations.
Defective graphene allows only protons to pass through
A team of scientists led by Franz Geiger of Northwestern University discovered that graphene could serve as a proton-selective permeable membrane, improving hydrogen fuel cells. Findings of the study were published in the latest issue of the journal Nature Communications. The study shows unprecedented movement of protons through atomic-scale defects in graphene.
Defective graphene acts as pores through which protons (and only protons) can pass from one side of the membrane to another in just a few seconds. It may help overcome a major hurdle in improving hydrogen fuel cells. Naturally occurring tiny defects in graphene, in which a carbon atom is missing, trigger a chemical reaction that lets protons pass from one side to another.
Graphene could be useful in every form
It doesn’t permit through any other molecules protons come from. Researchers said tiny holes in graphene make it a proton-selective membrane that could lead to a simpler mechanism for designing hydrogen fuel cells. Separating protons from hydrogen is a major challenge in fuel cell technology. Franz Geiger said his discovery opens doors for the further graphene development across the energy economy.
Fuel cells face a lot of issues from fleeting efficiency to the cumbersome size. Structural gaps in these thin carbon sheets could lead to improvements in production, transportation and use of energy. Researchers said larger holes could be made in graphene to allow water molecules to pass through, but not contaminants like salt, bacteria, toxins and viruses.
Manufacturing perfect, unbroken sheets of graphene is still difficult. But the latest discovery shows that the material could be useful in every form, including the defective one.