Picture of (a) nAg membrane and (b) control membranes showing the E. coli stained by DAPI. Cell growth was significantly inhibited in the presence of nAg in membranes.
Ensuring inexpensive and clean water for a growing global population is one of the Millennium Development Goals of the United Nations. We seek to help meet this challenge by developing and applying nanotechnologies that are economically feasible and easy to use in decentralized water and wastewater treatment and reuse systems. Here, we examined (1) fullerene-based nano photocatalysts (C60 aminofullerenes and C60 aminofullerene-coated silica gel) for their photocatalytic activity; (2) nano-sized magnetite for its adsorptivity; and (3) disinfection of viruses by nAg-doped TiO2 (nAg/TiO2), SiO2-doped TiO2 (SiO2-TiO2), and TiO2-coated carbon nanotubes (CNT-TiO2). Through this research, we successfully immobilized bis-, tetrakis-, and hexakis C60 aminofullerenes on easily-separable and recyclable silica gel and showed that the immobilization on silica gel significantly enhances singlet oxygen (1O2) production in the aqueous medium. C60 aminofullerene-coated silica was readily photoexcited with visible light, which will enable photocatalytic degradation of water pollutants and disinfection with solar irradiation. The significance of this finding is the potential to develop a photocatalytic system that is independent from extensive infrastructure (e.g., electricity). We also showed that the kinetics for virus inactivation by ultraviolet light can be accelerated in the presence of nAg/TiO and SiO2-TiO2 compared to commercial available Degussa P25 TiO2. Drastic decrease in virus inactivation efficacy in the presence of excess methanol suggested OH radical production by such modified TiO2 was responsible for the enhanced virus inactivation kinetics. We also synthesized nano-magnetite-coated polysulfone membranes, which showed high performance for viral removal.
6100 Main St MS-63, Space Science Building Rm 337, Houston, Texas 77005-1827
Mailing Address: P.O. Box 1892, Houston, Texas 77251-1892