Researchers created a convenient new way to visualize defect on layers of graphene by mapping the surface with a contrast agent.
The team of scientists developed a tomography procedure that revealed organized defect patterns on the surfaces of carbon material, the Institute of Organic Chemistry, Russian Academy of Sciences reported.
Graphene is an incredibly thin and strong material that also possesses useful electrical and thermal characteristics. The problem is that for most applications, the graphene must be perfect or have a controlled number of defects. In reality, ideal graphene is extremely difficult to produce, and finding defects on its surface is a major challenge. Scanning the entire area of a graphene sheet to detect defect is time consuming a faulty.
To remedy this, the researchers revealed a specific contrast agent (soluble palladium complex) that attaches itself to defects on the carbon surface, allowing for detection. The Pd attachment triggers the formation of nanoparticles that can be spotted by a routine electron microscope. The method allowed defect sites on a carbon surface to be mapped in three-dimensional space with high resolution and stunning contrast.
The method also can not only detect carbon defects due to morphology, but also those caused by disparities in chemical reactivity. Mapping carbon reactivity centers with "Pd markers" revealed the reactivity of the graphene layers. The study also highlighted the spatial complexity of carbon material at the nanoscale.
This new tomography method could have applications in the medical field, such as allowing physicians to run diagnostics of materials at an atomic scale.
The findings were published in a recent edition of the journal Chemical Science.
