The Cohen-Karni lab has published numerous papers investigating the properties of novel carbon-based materials synthesized in our own materials synthesis facility. Specifically, 3D nanocarbons have become a prominent choice as electrocatalysts due to their:
- Morphology
- Electrical properties
- Surface functionalities
Fundamental Properties of Nanowire-Templated Three-Dimensional Fuzzy Graphene
Through a finely controlled synthesis process, we have developed a novel 3D nanocarbon material named nanowire-templated three-dimensional fuzzy graphene (NT-3DFG). The value in NT-3DFG comes from its exceptionally large electrochemical surface area.
Nanowire Templated 3D Fuzzy Graphene (NT-3DFG)
We have shown highly controlled synthesis by varying graphene growth conditions in regards to (1) CH4 partial pressure, and (2) synthesis time such that the electrical properties of the material can be optimized for a given application and needed material properties.
Modular conductivity of NT-3DFG
This fine-tuned control allows for the variable growth of NT-3DFG in regards to:
- Flake size
- Density
- Electrical properties
NT-3DFG for Electrocatalysis and Biosensing
Understanding a material’s fundamental properties is essential to developing the next generation of functional optical, electrical and/or electrochemical platforms. We have elucidated that NT-3DFG facilitates electron-transport from two integrated contributions:
- Intra-plane graphitic shell conduction
- Inter-planar variable range hopping
Electron Transport of NT-3DFG
Through our finely controlled synthesis process, we establish a correlation between NT-3DFG edge density and activity toward two-electron oxygen reduction reactions (ORR) with a selectivity of ca. 94%. The developed methods and materials will also be used for future energy storage materials and devices. Our experimental and theoretical results predict that zigzag edge sites with high carbonyl group coverage, as well as other edge configurations with a similar local coordination environment, may enable selective, two-electron ORR. Our generated knowledge has cross-disciplinary impact in the Cohen-Karni lab towards biomedical research, such as the development of biosensors and other electrocatalysis platforms.
Tailoring the Electrocatalytic Modulation of NT-3DFG
Nanocrawlers
Novel synthesis of in-plane Ge nanowires (or Ge nanocrawlers) on single layer graphene substrates.
Understanding of the fundamental thermodynamic growth enables crystalline graphene growth and new electronic interfaces between group IV materials and graphene, potentially toward designing new geometries for hybrid materials sensors.
