Graphene flaws improve gas sensing sensitivity

The imperfections have unique electronic properties that the researchers were reportedly able to exploit to increase sensitivity to absorbed gas molecules by 300 times.

The study - conducted by researchers at the University at Illinois, Chicago (UIC) and Purdue University, Indiana - is available online in Nature Communications.

According to UIC, when a graphene lattice or sheet is formed, its polycrystalline structure has random boundaries between the single-crystal grains. The properties of the lattice are significantly affected by these grain boundaries, said Amin Salehi-Khojin, UIC assistant professor of mechanical and industrial engineering and principal investigator on the study.

In many applications, grain boundaries are considered faults because they scatter electrons and may weaken the lattice but Salehi-Khojin and his colleagues showed that these imperfections are important to the working of graphene-based gas sensors. They created a micron-sized, individual graphene grain boundary in order to probe its electronic properties and study its role in gas sensing.