Carve out a Sustainable Future: Rational Design of Carbon Nano-Materials for Water Purification

Carve Out A Sustainable Future: Rational Design of Carbon Nano-Materials for Water Purification and Energy Production

Chongzheng Na Assistant Professor Department of Civil and Environmental Engineering & Earth Sciences University of Notre Dame

Date: October 11, 2013 (Friday) Time: 4:00 pm Location: 356 Fitzpatrick Hall

Materials that are less than 100 nanometers in size have attracted increasing attention as new tools for solving engineering challenges. In the nanometer range, materials often exhibit unique properties their bulk counterparts do not have. Can these properties be utilized to create innovative solutions for challenges associated with water security and solar energy fixation? Can such solutions be devised through rational design? In this talk, I will attempt to answer these questions through two examples. In the first example, carbon nanotubes (CNTs) decorated with superparamagnetic iron oxide nanoparticles (SPIONs) are developed as a reusable material for cleaning up water that is contaminated during oil and gas productions. Using an external magnetic field as control, SPION-CNTs can rapidly separate oil from water and then recover oil by forming Pickering emulsions. In the second example, titanium dioxide (TiO2) nanoparticles are welded on CNT surfaces to be used as a composite material for hydrogen generation from photocatalytic water splitting. Compared to bare TiO2, CNT-supported TiO2 has improved efficiency thanks to CNTs’ nanoscale conductivity that separates photo-generated electron-hole pairs, thereby extending the pairs’ lifetime and improving their reactivity. An important lesson learned from these examples is the concept of hierarchical design. By integrating nanomaterials of different dimensions and properties, a structured composite can be made to achieve a comprehensive engineering objective that requires multi-functionality. Biosketch of Chongzheng Na Chongzheng Na obtained his bachelor’s, master’s, and doctoral degrees – all in Environmental Engineering – from Tsinghua University (China), Pennsylvania State University, and the University of Michigan, respectively. He was further trained in Environmental Chemistry at Harvard University as Postdoctoral Fellow before joining the University of Notre Dame as Assistant Professor in 2009. His primary research interest is designing new nanomaterials for improving water security, energy production, environmental quality, and human health.