1. Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, Departments of Chemistry and Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801