Electrochemical Energy Storage
Our current efforts to enhance ion and electron transport in electrochemical energy storage systems are focused on decreasing the diffusion distance through the use of 3D nanostructured electrodes. Nanocarbon materials offer significant promise in synthesizing highly conductive, low-density 3D electrodes with tunable textural properties. We seek to establish inter-relationships between the properties of the 3D electrode and the electrochemical performance.
Synthesis of Carbon Nanomaterials by Chemical Vapor Deposition
Many important applications of carbon nanotubes (CNTs) require their synthesis on nontraditional substrates with exquisite control of their geometry. We are developing an in-depth fundamental understanding of the nanoscale phenomena occurring during the growth process that will guide the fabrication of efficient catalysts. The approach involves surface analytical techniques, including in situ and ex situ electron microscopy and advanced spectroscopy, to probe the catalyst.
Photocatalytic Air Purification
Photocatalytic oxidation using semiconductors as catalysts has become an appealing approach as a green technology for environmental remediation. Nanocarbon-supported TiO2 composites have attracted significant interest due to the ability of nanocarbon to induce synergistic effects between the carbon phases and TiO2 that inhibits the recombination rate of the photogenerated electron-hole pair and red-shifts the photoresponse to the visible region. We are interested in understanding the CNT enhancement mechanisms and developing a pathway for the synthesis of low-cost and scalable visible-light-active CNT-based/TiO2 coatings for outdoor oxidation of pollutants.
Synthesis of Clean Fuels
Efficient catalyst systems are required to convert natural gas to higher hydrocarbons via Fischer-Tropsch synthesis. Such superior catalysts will require new supports that are characterized by high mesoporosity and thermal conductivity, as well as improved chemical stability. Given the outstanding physical and chemical properties of CNTs and graphene, the use of tunable 3D CNT-graphene hybrid structures as catalyst supports is being explored. These new supports will improve mass transport of reactants and products, heat dissipation during the exothermic reaction, and the stability of the catalyst.