Abstracts Book - IMRC 2018

• SF2-O012
GO/TIO2 NANOCOMPOSITES FOR ESCHERICHIA
COLI PHOTOCATALYTIC INACTIVATION: THE ROLE OF REACTIVE
OXYGEN SPECIES
Christeena Theresa Thomas 1 , Myriam Solís López 2 , Roberto Hernandez 2 , Martha Barajas
Aceves 3 , Jose Tapia Ramirez 4 , José Alvaro Chávez Carvayar 5 , Antonieta García Murillo 6 , Felipe de
Jesús Carillo 6 , Eleicer Ching 7 , Velumani Subramaniam 2
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV, Programa en
Nanociencias y Nanotecnología, Mexico. 2 Centro de Investigación y de Estudios Avanzados del
IPN - CINVESTAV, Departamento de Ingeniería Eléctrica, Mexico. 3 Centro de Investigación y de
Estudios Avanzados del IPN - CINVESTAV, Departamento de Biotecnología, Mexico. 4 Centro de
Investigación y de Estudios Avanzados del IPN - CINVESTAV, Genética y Biología Molecular,
Mexico. 5 Universidad Nacional Autónoma de México, Instituto de Investigaciones en
Materiales, Mexico. 6 Escuela Superior de Ingeniería Química e Industrias Extractivas, Ingeniero
Quimico Industrial, Mexico. 7 Universidad Tecnológica de Panamá, Departamento de Ciencias
Naturales, Panama.
Graphene Oxide/TiO 2 (GO/TiO 2 ) semiconducting nanocomposites was
synthesized and evaluated for the photocatalytic disinfection of Escherichia coli.
It was used TiO 2 to functionalize GO to increase its efficiency in the disinfection
process. The synthesized nanocomposites were characterized by scanning
electron microscope (SEM) for the surface morphology, X- ray diffraction (XRD)
for the crystal structure, Raman spectroscopy for the structural analysis and UV-
Vis diffuse reflectance (DR) to determine the band gap in GO/TiO 2
semiconducting nanocomposites. The disinfection tests were carried out using
a solar simulator under visible light irradiation. The role of reactive oxygen
species (ROS) was analyzed by a scavenger study. The XRD results show the
increase in the concentration of GO can lead to the partial reduction of GO to
graphene. According to SEM analysis in all the samples, it is possible to observe
a homogeneous distribution of TiO 2 nanoparticles over GO sheets. Through
Raman analysis, the corresponding D and G bands for GO was identified
showing the crystalline quality of the nanocomposite. The characterization
techniques reveal the influence of embedding TiO 2 in GO to enhance
photocatalytic disinfection. The formed nanocomposite reduces the electronhole
pair recombination rate, and with the functional modification of the GO,
then the efficiency on photocatalytic inactivation was improved. The ROS
responsible for the bactericidal effect were identified.