Abstracts Book - IMRC 2018

• SA1-P020
REDUCED GRAPHENE OXIDE/TITANIUM DIOXIDE COMPOSITE AS
ANODE FOR Li-ion BATTERIES
Guillermo Santamaria Juarez 1 , Estela Gomez Barojas 1 , Enrique Quiroga González 2 , Enrique
Sánchez Mora 2 , Mildred Quintana 3 , Juana Deisy Santamaria Juarez 4
1
Benemerita Universidad Autonoma de Puebla, Centro en investigación en Dispositivos
Semiconductores, Mexico. 2 Benemerita Universidad Autonoma de Puebla, Institute of Physics,
Mexico. 3 Universidad Autónoma de San Luis Potosí, Departamneto de Fisica, Mexico.
4 Benemerita Universidad Autonoma de Puebla, School of Chemical Engineering, Mexico.
We report a synthesis procedure of rGO/TiO2 composites as a possible highperformance
anode material of Li-ion batteries. Graphene oxide (GO) is
synthesized graphite powder using a modified (by us) Hummer’s method and
dispersed in DI water. Separately, commercial TiO2 nanoparticles (P25 TiO2,
Degussa) have been thermally treated in order to obtain a clean TiO2 surface.
Nanocomposites of rGO/TiO2 were prepared by the solvothermal method,
mixing GO with clean TiO2 powder. EDS Elemental mapping in TEM of the
composites reveals that oxygen is present in the graphene sheets, which
present several defects caused by bending (as confirmed by HRTEM). TEM
micrographs show the TiO2 nanoparticles homogenously dispersed onto the
reduced graphene oxide sheets. The defectual and oxidized surface may
present several points for the chemisorption of TiO2, as suggested by FTIR
spectra, which presents lines originated -OH stretching (3410 cm -1 ), carboxylates
or ketones C=O stretching (1734 cm -1 ), water -OH bending and C=C stretching
(1629 cm -1 ), alcoholic C-OH bending (1420 cm -1 ), epoxide C-O-C or phenolic C-O-
H stretching (1227 cm -1 ), and C-O stretching (1055 cm -1 ). XPS spectra of the
composites also presents sub-bands of C probably related to the presence of
TiO2. Raman spectra of GO show D and G lines localized at approx. 1344 and
1580 cm -1 , confirming the lattice distortion of graphene. In the Raman spectrum
of rGO/TiO2 composite, the D band is broadened and redshifted with respect to
that of GO, confirming the interaction of graphene with TiO2. Additional bands
at 151 and 405 cm -1 indicates that TiO2 is present with anatase structure. Based
in the characterization results, we conclude that the rGO/TiO2 composites were
synthesized successfully. GO facilitates the electron transfer to TiO2 when used
as anode in Li ion batteries; chemisorption may enhance the electrical contact.
This composite may present an enhanced Li-ion insertion/extraction rate in
comparison to pure TiO2 anodes just containing some carbon black additive.