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Influence of GnPs concentration on the phase transformation and electrical behavior in TiO2-Al2O3.

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Title: Influence of GnPs concentration on the phase transformation and electrical behavior in TiO2-Al2O3.
Authors: Espinosa-González, C.G.1 (AUTHOR) claudia.espinosa@correo.uady.mx, Gallegos-Hernández, D.J.2 (AUTHOR), Zurita-Yduarte, A.J.2 (AUTHOR), Benítez-Benítez, J.L.2 (AUTHOR), Sierra-Gómez, U.A.3 (AUTHOR), Herrera-Franco, P.J.4 (AUTHOR), Carrera-Figueiras, C.5 (AUTHOR), Esparza-Ruiz, A.5 (AUTHOR), Falconi-Calderón, R.2 (AUTHOR), Labrada-Delgado, G.J.6 (AUTHOR)
Source: Ceramics International. May2026:Part A, Vol. 52 Issue 12, p18219-18231. 13p.
Subjects: Phase transitions, Electric properties, Electric conductivity, Aluminum oxide composites, Graphene, Surface morphology, Sol-gel processes
Abstract: Synthesis of the mixed oxide TiO 2 -Al 2 O 3 loaded with graphene nanoplatelets (GnPs) to obtain the ternary material TiO 2 -Al 2 O 3 -GnPs via the sol-gel method was carried out under soft conditions and at room temperature. Different proportions of GnPs, from 0.05 wt% to 1.0 wt %, were added to the mixed oxide to promote electrical properties in the resulting ternary material. The textural characterization was carried out by N 2 gas adsorption/desorption technique, XRD analysis was used to determine the structures in calcined and sintered materials, and transmission electron microscopy (TEM) used to determine the morphology of materials. The material with the highest specific area obtained was TAG5 (containing 0.75 wt % of GnPs) with 379 m2/g. The XRD technique revealed a amorphous material when calcined at 500 °C, and signals corresponding to anatase for TiO 2 and gamma for Al 2 O 3 were detected; GnPs in any proportion used did not affect the amorphous structure of the ternary material. In the case of ternary materials sintered at 750 °C, an additional rutile phase was also confirmed for TiO 2 , the evident anatase-rutile transformation progressed when the GnPs proportion was increased up to 0.75 wt%, and then at 1.0 wt% of GnPs the anatase-rutile transformation was stopped. According to the TEM microscopy observations, all samples with different proportions of GnPs showed a similar morphology in which the mixed oxide appears as a continuous phase without segregated phases and the material coats the GnPs particles. Results obtained by the four-point method showed a random resistive behavior independent of the GnPs concentration used in the calcined samples. On the other hand, for the sintered materials the resistive behavior reached its highest level at 2181 × 104 Ω•m at GnPs concentration of 0.5 wt %, and the material's conductive character was restored at 43.6 × 104 Ω•m when the GnPs concentration was at 1.0 wt %. The development that was demonstrated enables ternary materials with structural and electrically conductive properties that boost opportunities for ceramic matrix materials in broad applications, such as energy storage devices, electrochemical capacitors, or supercapacitors. [Display omitted] [ABSTRACT FROM AUTHOR]
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Database: Engineering Source
Description
Abstract:Synthesis of the mixed oxide TiO 2 -Al 2 O 3 loaded with graphene nanoplatelets (GnPs) to obtain the ternary material TiO 2 -Al 2 O 3 -GnPs via the sol-gel method was carried out under soft conditions and at room temperature. Different proportions of GnPs, from 0.05 wt% to 1.0 wt %, were added to the mixed oxide to promote electrical properties in the resulting ternary material. The textural characterization was carried out by N 2 gas adsorption/desorption technique, XRD analysis was used to determine the structures in calcined and sintered materials, and transmission electron microscopy (TEM) used to determine the morphology of materials. The material with the highest specific area obtained was TAG5 (containing 0.75 wt % of GnPs) with 379 m2/g. The XRD technique revealed a amorphous material when calcined at 500 °C, and signals corresponding to anatase for TiO 2 and gamma for Al 2 O 3 were detected; GnPs in any proportion used did not affect the amorphous structure of the ternary material. In the case of ternary materials sintered at 750 °C, an additional rutile phase was also confirmed for TiO 2 , the evident anatase-rutile transformation progressed when the GnPs proportion was increased up to 0.75 wt%, and then at 1.0 wt% of GnPs the anatase-rutile transformation was stopped. According to the TEM microscopy observations, all samples with different proportions of GnPs showed a similar morphology in which the mixed oxide appears as a continuous phase without segregated phases and the material coats the GnPs particles. Results obtained by the four-point method showed a random resistive behavior independent of the GnPs concentration used in the calcined samples. On the other hand, for the sintered materials the resistive behavior reached its highest level at 2181 × 104 Ω•m at GnPs concentration of 0.5 wt %, and the material's conductive character was restored at 43.6 × 104 Ω•m when the GnPs concentration was at 1.0 wt %. The development that was demonstrated enables ternary materials with structural and electrically conductive properties that boost opportunities for ceramic matrix materials in broad applications, such as energy storage devices, electrochemical capacitors, or supercapacitors. [Display omitted] [ABSTRACT FROM AUTHOR]
ISSN:02728842
DOI:10.1016/j.ceramint.2026.02.381