I. Graphene-Based Membranes for Water Purification, Wastewater Treatment, and Osmotic Energy (Blue Energy) Harvesting
Zhao group is interested in nanoconfined water in carbon nanotubes and graphene membranes motivated by his bilayer lipid water studies in 2006 during the sabbatical in Professor Mike Fayer’s group at Stanford University. It is natural for Zhao to turn his interest to water purification as the demand for safe, clean water grows globally and to search for easier, cost-effective ways to develop water filtration systems using 2D layered nanomaterials (graphene, MoS2, MXenes) and MOFs. Supported by a Research Cluster Seed Grant and Signature Experience Grants of UA Little Rock, a user fund from the Center for Integrated Nanotechnologies (CINT) of DOE, and a grant from the NASA Small Business Innovation Research and Small Business Technology Transfer programs, Zhao and his students have been using graphene oxide and reduced graphene oxide (RGO) for membrane filtration and have developed robust forward osmotic RGO membranes, suitable for low energy water purification, wastewater management, and blue energy harvesting.
Link to the Article Highlighting the Graphene Research.
Link to the video showing fast filtration with low pressure.
Link to the video showing robust membranes by Tape-Peeling.
Link to Blue Energy to light up LEDs using a Foward Osmosis process which reduces the feed solution volume and simultaneously harvests the osmotic energy.
Selected Research Groups Working on Membrane Filtration
Elimelech Research Group at Yale University/Rice University
Baoxia Mi Group at UC Berkeley
Yongsheng Chen Group at Gatech.
Dan Li Group at University of Melbourne.
Julie Korak Research Group at University of Colorado Boulder.
Scott Mauger at NREL for Rol-to-Roll coating for membrane manufacturing.
Sankar Nair Research Group at Gatech for large area GO membranes.
II. Nanostructure-Assisted Water Splitting for Hydrogen Production and Storage:
Photoelectrochemical (PEC) hydrogen production is the cleanest method with great promise. However, there are great challenges to find PEC materials that are low-cost and efficient enough to generate hydrogen at a price competitive with fossil fuels. In addition, hydrogen storage is also crucial for hydrogen economy. Carbon nanostructures derived from earth-abundant biomass may be an efficient scaffold offering crucial morphology controls for growing size-controllable PEC nanocatalysts. They may also serve as hydrogen storage materials, meeting the aspects of high storage capacity, good reversibility, cost effectiveness, and abundant availability. Building upon our recent progress in fabrication of low-cost hybrid 3D nanomaterials for hydrogen production (published at the Journal of The Electrochemical Society) and carbon nanostructure production from cyanobacteria and algae, we are addressing the key bottlenecks in the hydrogen production and storage with two aims: (1) growing and assembling PEC nanomaterials embedded in biomass (algae, cyanobacteria, silk protein, etc.)-derived 3D carbon nanostructures for hydrogen production; and (2) synthesizing nanoscale metal/metal oxides embedded in biomass-derived carbon nanostructures for hydrogen storage.
Link to our Nanotechnology Section with an Emphasis on Energy Applications held in 2017 FACSS (SCIX 2017)
Link to our Symposium of Biotemplate-Based Nanomaterials for Energy Applications held in 2016 FACSS (SCIX 2016)
III. Optical Nonlinearity and Structure Relationships of Single-Walled Carbon Nanotubes:
We Synthesize and functionalize soluble single-walled carbon nanotubes (SWNTs) and measure nonlinear optical properties of the SWNTs by using multi-resonant four wave mixing spectroscopy for photonic device applications and optical sensors. This program was supported by Army Research Office (ARO) of DoD. The project was in collaboration with Dr. Pehr Pehrsson at Naval Research Laboratory and Prof. Jie Liu at Duke University. We have found a facile chemical oxidative method to synthesize water-soluble SWNTs and observed that the optical absorption of the SWNTs reversibly responds to pH. The results point out the opportunity for using the SWNTs for pH sensors. This work was published in the Journal of American Chemical Society. More recently, we have observed that water-soluble SWNTs reversibly respond to hydrogen peroxide. So we move into a new direction for development of SWNTs-based optical biosensors which may be used for potential optical nanosensors when they are in combination with nanolasers, nano waveguides and nano optical fibers. Based on molecular recognition, enzyme-modified SWNTs for sensing several important metabolic compounds such as glucose, lactate and cholesterol, and three representative biospecific pair systems including single stranded (ss)-DNA hybridization, biotin/streptavidin and calmodulin/Ca2+ are investigated by optical measurements.
Selected Research Groups Working on SWNTs and Nonlinear Optical Materials
Lieber’s Group
Louis Brus’s Group at Columbia University
Jie Liu at Duke University
Hongjie Dai at Stanford University
Marder’s Group at University of Colorado Boulder
Boyd’s Group at University of Rochester
Organizer of Applications of Nanotubes and Nanowires Symposium at 2007 MRS Spring Meeting
Symposium EE: Applications of Nanotubes and Nanowires
Chair of Carbon Nanotube Separation Symposium at FACSS
First Symposium of Carbon Nanotube Separation held in 2003 FACSS
Second Symposium of Carbon Nanotube Separation held in 2004 FACSS
Third Symposium of Carbon Nanotube Separation held in 2005 FACSS
Fourth Symposium of Carbon Nanotube Separation held in 2006 FACSS
Organizer of Nanoscience and Nanomaterials Symposia at FACSS
Nanoscience and Nanomaterials Symposia held in 2004 FACSS
Nanoscience Symposia held in 2005 FACSS
Nanoscience Symposia held in 2006 FACSS
Nanoscience Workshop at UA-Little Rock, 2006
IV. Development of Novel Doubly Vibrationally Enhanced (DOVE) Four Wave Mixing Spectroscopy:
We use DOVE four wave mixing spectroscopy as a powerful analytical tool to measure and identify multisites and multicomponents in complex systems. This research relies on a newly developed analytical methodology-Doubly Vibrationally Enhanced (DOVE) Infrared Four Wave Mixing Spectroscopy. This method is based on nuclear polarization and is analogous to two-dimensional NMR which measures the cross peaks induced by intra- and/or intermolecular interactions. The DOVE methods have the unique capabilities: 1) mode selection, 2) line narrowing, 3) isotope selection, 4) suppression of solvent background. This work is collaboration with Prof. John Wright of UW-Madison.
Link to Articles Highlighting the DOVE Research Work
Selected Research Groups Working on Coherent Multi-Dimensional Laser Spectroscopy
John Wright at University of Wisconsin-Madison
Mukamel’s Group at University of California-Irvine
Fayer’s Group at Stanford University
David Jonas’s Group at University of Colorado Boulder
Tokmakoff’s Group at UC
Fleming’s Group at UC-Berkeley
Blank’s Group at University of Minnesoda
Dlott’s Group at University of Illinois-Urbana
Link to our Symposium of Advances in Applied Nonlinear Spectroscopy held in 2023 Fall ACS National Meeting
Link to our Symposium of Coherent Multidimensional Spectroscopy in Materials Science held in 2017 Spring ACS National Meeting
Symposium of Coherent Multidimensional Spectroscopy for Materials Science held in 2014 Spring ACS National Meeting
Symposium of Coherent 2D Vibrational Spectroscopy held in 2004 FACSS
V. Applications of 2D IR Correlation Spectroscopy for Molecular Interaction Study:
We use 2D infrared correlation spectroscopy to study the fundamental of the near infrared combination bands of organic compounds and biological materials, and to probe molecular interactions among glucose, proteins and novel carbon nanotubes. This project was supported by Research Corporation. The study may lead to a new understanding of these combination bands and provide a new analytical tool for materials identification and molecular interaction study. Traditional FT-IR spectroscopy is a research tool in this research that is particularly suitable for undergraduate students. We have made new progress in a representative biological system composed of glucose, bovine serum albumin and triacetin as well as in the new exciting area of the molecular interaction study of glucose with water-soluble SWNTs. We have identified new features of glucose anomers in near IR by using 2D IR correlation spectroscopy and have probed selected interaction of functionalized SWNTs with the glucose anomers.
First Symposium of 2D Correlation Spectroscopy held in 2002 FACSS
Second Symposium of 2D Correlation Spectroscopy held in 2004 FACSS
Third Symposium of 2D Correlation Spectroscopy held in 2006 FACSS
International Symposium on Two-Dimensional Correlation Spectroscopy (2DCOS-II) 21st -23rd August, 2003, Nottingham, UK.
International Symposium on Two-Dimensional Correlation Spectroscopy (2DCOS-III) 12 -14 August, 2005, Delavan, Wisconsin, USA.
VI. Synthesis and Study of Novel Nanostructural Lanthanide Ion-Doped Materials for Optical Data Storage, Signal Processing and Optical Sensors:
Recently, we have synthesized new BaFCl:Eu3+ and BaFCl:Eu3+,Tb3+ crystals whose microstructures have been chemically modified by different defects doping. Persistent spectral hole-burning has been observed at temperature as high as 150 K and multi-holes have been burnt in BaFCl:Eu3+. It has been anticipated that by controlling the particle size in nanoscale, more intriguing properties of this material will be discovered. Further study by exploring the enhanced band gap fluorescence of individual SWNTs sensitized by lanthanide ions such as Gd3+ and Tb3+ has been under way for optical sensors. The research has been in collaboration with Dr. Guokui Liu at Argonne National Laboratory.
Link to Other Selected Research Groups:
Hebard’s Group at University of Florida-Spintronics
Tang’s Group at University of Wyoming-Magnetic Nanomaterials
Dr. Stephen K. Doorn at Center for Integrated Nanotechnologies, Los Alamos National Laboratory