Hierarchical 3D Functional Nanocarbon for Electrochemical Storage and Electrocatalysis
We have been able to directly grow 1D nanostructures such as carbon nanofibers and ZnO nanowires on the current collector , Cu, stainless steel and carbon cloth. We have successfully developed a vapor transport method to deposit an electrocatalyst, i.e., FeN4C on 3D carbon and demonstrated that this new platform exhibitsexcellent electrolysis capability for oxygen reduction reaction (ORR), comparable to Pt/C in an alkaline media. We have revealed for the first time that grafting non-conductive SiOx with proper chemical structure on carbon surface can alter carbon electronic structure and consequently enhance ORR performance.
Accumulative knowledge and significant advancements in nanocarbon synthesis and functionalization have fueled research aimed at developing 3D carbon based electrodes for electrochemical reactions. To achieve high volumetric activity for electrochemical reactions, the following two prerequisites need to be met simultaneously:
- Evenly and densely populated active species that are electrically connected to a large surface area porous 3D carbon surface and in the meantime physically in contact with the required reactants for chemical reactions.
- Facile mass diffusion of drastically different reactant and products in a common porous medium.
We are developing 3D free-standing carbon-based electrodes that will meet these requirements. For instance, we are investigating the use of 1D inorganic nanostructures on carbon cloth as a template to form a 3D mesoporous carbon structure with well-defined porous architectures that are mechanically stable. We are exploiting a variety of methods to graft a thin layer of electrocatalytic or electrochemical species on as-formed 3D carbon surfaces.