Functionalized Graphene Derivatives and TiO2 for High Visible Light Photodegradation of Azo Dyes
Metadatos
Mostrar el registro completo del ítemAutor
Pérez Molina, Álvaro; Morales Torres, Sergio; Maldonado Hodar, Francisco José; Pastrana Martínez, Luisa MaríaEditorial
MDPI
Materia
Graphene oxide TiO2 Heteroatom doping Photocatalysis Orange G Scavengers
Fecha
2020-06-03Referencia bibliográfica
Pérez-Molina, Á., Morales-Torres, S., Maldonado-Hódar, F. J., & Pastrana-Martínez, L. M. (2020). Functionalized Graphene Derivatives and TiO2 for High Visible Light Photodegradation of Azo Dyes. Nanomaterials, 10(6), 1106. [doi:10.3390/nano10061106]
Patrocinador
ERDF/Ministry of Science, Innovation and Universities-State Research Agency RTI2018-099224-B-I00Resumen
Functionalized graphene derivatives including graphene oxide (GO), reduced graphene
oxide (rGO), and heteroatom (nitrogen/sulphur (N/S) or boron (B))-doped graphene were used to
synthesize composites with TiO2 (T). The photocatalytic performance of composites was assessed
for the degradation of Orange G dye (OG) under simulated solar light. All the prepared graphene
derivatives—TiO2 composites showed better photocatalytic performance than bare TiO2. A higher
photocatalytic activity was found for the composites containing GO and N/S co-doped rGO
(kapp = 109.2 × 10−3 and 48.4 × 10−3 min−1
, for GO-T and rGONS-T, respectively). The influence of
both initial solution pH and the reactive species involved in the OG degradation pathway were
studied. The photocatalytic activity of the samples decreased with the increase of the initial pH
(from 3.0 to 10.0) due to the occurrence of electrostatic repulsive forces between the photocatalysts
surface and the molecules of OG, both negatively charged. The use of selective scavengers showed
that although the photogenerated holes dominate the degradation mechanism, radicals and singlet
oxygen also participate in the OG degradation pathway. In addition, reutilization experiments
indicated that the samples were stable under the reaction conditions used.