1. Department of Geological Sciences, The University of Texas at El Paso, El Paso, Texas 79968, United States
2. Virginia Tech National Center for Earth and Environmental Nanotechnology (NanoEarth), Blacksburg, Virginia 24061, United States
3. Chemistry & Biochemistry Department, The University of Texas at El Paso, El Paso, Texas 79968, United States
4. University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, El Paso, Texas 79968, United States
5. Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States