Nanoscale insights into the structure of solution-processed graphene by x-ray scattering

Chemical exfoliation is an attractive approach for the synthesis of graphene due to its low cost and simplicity. However, challenges still remain in the characterization of solution-processed graphene, in particular with atomic resolution. Through this work we demonstrate the x-ray pair distribution function as a novel approach to study solution-processed graphene or other 2D materials with atomic resolution, directly in solution, produced by liquid-phase and electrochemical exfoliations. The results show the disappearance of long-range atomic correlations, in both cases, confirming the production of single and few-layer graphene. In addition, a considerable ring distortion has been observed as compared to graphite, irrespective of the solvent used: the normal surface angle to the sheet of the powder sample should be less than 6 degrees, compatible with ripples formation observed in suspended graphene. We attribute this effect to the interaction of solvent molecules with the graphene nanosheets.

Automated summary

Chemical exfoliation is a cost-effective and simple method for synthesizing graphene. In this work, we demonstrate the use of x-ray pair distribution function to study solution-processed graphene or other 2D materials with atomic resolution, directly in solution. The results confirm the production of single and few-layer graphene, and also reveal a considerable ring distortion caused by the interaction between solvent molecules and graphene nanosheets.