Dr. Cates’ research focuses on the development of advanced materials for environmental technology and public health applications, with an emphasis on optical materials and photocatalysts. The main achievement of his Ph.D. and postdoctoral work was in pioneering the field of visible-to-UVC upconversion phosphors – inorganic luminescent materials that are capable of converting ordinary visible light into germicidal ultraviolet radiation. He has contributed to fundamental advances in the design and understanding of light conversion by Pr3+-doped crystals and developed proof-of-concept material systems for applying upconversion to sustainable light-activated antimicrobial surfaces.
His current research interests include: (1) fundamental phosphor development for improving the efficiency of visible-to-UV upconversion; (2) development of visible light-activated photocatalysts; (3) microbial inhibition and singlet oxygen photosensitization by silicon nanocrystals; and (4) material technologies for enhancing solar water disinfection for the developing world. This research integrates environmental engineering with materials science and physical chemistry. Students in the Cates Lab will utilize solid state synthesis methods, laser spectroscopy, wet chemical experiments, microbial enumeration, and crystallography.
EES 8030 Physiochemical Operations in Water and Wastewater Treatment Systems
Cates, S.L., E.L. Cates, M. Cho, J.H. Kim. 2014. “Synthesis and characterization of visible-to-UVC upconversion antimicrobial ceramics”. Environmental Science & Technology, 48(4) p. 2290-2297.
Cates, E.L., J.H. Kim. 2013. “Upconversion under polychromatic excitation: Y2SiO5:Pr3+,Li+ converts violet, cyan, green, and yellow light into UVC.” Optical Materials, 35(12) p. 2347-2351.
Cates, E.L., S.L. Chinnapongse, J.H. Kim, J.H. Kim. 2012. “Engineering light: Advances in wavelength conversion materials for energy and environmental technology (Critical Review)”. Environmental Science & Technology, 46(22) p. 12316-12328.
Cates, E.L., A.P. Wilkinson, J.H. Kim. 2012. “Delineating mechanisms of upconversion enhancement by Li+ doping in Y2SiO5:Pr3+”. Journal of Physical Chemistry C, 116(23) p. 12772-12778.
Cates, E.L., M. Cho, J.H. Kim. 2011. “Converting visible light into UVC: Microbial inactivation by Pr3+-activated upconversion materials”. Environmental Science & Technology, 45(8) p. 3680 – 3686.
Cho, M., E.L. Cates, and J.H. Kim. 2011 “Inactivation and surface interactions of MS-2 bacteriophage in a TiO2 photoelectrocatalytic reactor”. Water Research, 45(5) p. 2104 – 2110.
Cates, E.L., S. Patch, J. Cox, M. Westphal, J. Calabria. 2009. “Field evaluation of a proprietary stormwater treatment system: Removal efficiency and relationships to peak flow, season, and dry time”. ASCE Journal of Environmental Engineering, 135(7) p. 511-517.
2013 Best Student Paper, ACS National Meeting, Division of Environmental Chemistry (coauthor)
2011 Best Environmental Technology Article of 2011, Environmental Science & Technology (first author)
2011 Best presentation, Georgia Tech Environmental Engineering Research Internship Program (awarded to high school student mentees)
2010 Best Student Paper, ACS National Meeting, Division of Environmental Chemistry (first author)
2008 Georgia Power Fellowship in Environmental Engineering
2007 Environmental Studies Departmental Distinction (UNC-A)
2007 University Research Scholar (UNC-A)
2006 Environmental Quality Institute Research Assistantship (UNC-A)
2005 North Carolina Beautiful Fellowship in Pollution Control