Research interests

Graphene production and post-processing techniques

There is a large family of materials which we refer to as graphene-based materials which differ in terms of their morphology, lateral size, thickness and the number and type of functional groups and/or defects. Our group is interested in learning how to better study and control these properties such that graphene-based materials can be tailored to specific applications. Using various chemical, electrochemical, thermal and mechanical methods, we study how the processing trajectory dictates the final material structure using a combination of microscopy and state-of-the-art analytical techniques.

Directed assembly of 2D nanomaterials at the air-water interface

Current nanomaterial film forming technologies rely on either capital intensive processes such as vapor deposition or approaches based on filtration or evaporation which yield poor control over film structure and function. For example, growth of graphene by vapor deposition is limited to a small set of substrates such as copper or SiC (silicon carbide) and requires tedious steps to transfer films to other substrates such as plastics or glass. Our group is working to develop coating techniques which rely on manipulating atomically thin, floating, micron-sized graphene sheets and other 2D materials at the air-water interface. These films can be packed to arbitrary densities and deposited on effectively any solid or porous substrates as single layers or layer-by-layer to create well-defined, functional multi-layer structures or tailored heterojunctions. Using the approaches developed we expect to advance technologies such as the following:

  • Transparent conductors and electronic devices
  • Molecular blocking layers for packaging or corrosion prevention
  • Semi-permeable membranes for more efficient separations
  • 2D electrodes and well-defined nanocomposites for fundamental electrochemical characterization

Bottom-up assembly approaches for energy storage, sensing and electrocatalysis

Conductive nanomaterials such as graphene and carbon nanotubes are promising candidates for a variety of electrochemical devices due to their high specific surface area which leads to a high capacitance electrochemical supercapacitors, an electronic highway for poorly conducting battery materials or a scaffold for more efficient electrocatalysts. In this area, our group has two major research thrusts. The first focuses on mapping the intrinsic electrochemical response of a nanomaterial system using model 2D graphene-based electrodes to the more complex behavior in thick porous films. This involves the following research areas:

  • Model 2D electrode systems for fundamental studies
  • Layer-by-layer assembly techniques to build and study electrodes with controlled porosity
  • Using these systems to decouple intrinsic electrochemistry from the apparent porous response

Building on these model studies, our group develops methods based on colloidal processing and controlled aggregation to combine optimized materials with optimized electrode structures in order to advance a variety of next-generation electrochemical devices. In particular, we are interested in:

  • Nanocomposite anode/cathode designs for advanced batteries
  • Metal anode protection strategies
  • Printable supercapacitor/battery formulations compatible with advanced manufacturing