Diseño y optimización de las propiedades y características de materiales grafénicos

Abstract

In this thesis 0D, 1D and 2D graphene materials were synthesized and used to develop 2D and 3D architectures. Two methodologies were applied to obtain 2D materials, a chemical route and liquid phase exfoliation using graphitic and pregraphitic materials to obtain graphene oxide and graphene materials. Carbon nanotubes (1D carbon materials) were synthesized using an aerosol assisted chemical vapor deposition method. Graphene quantum dots (0D carbon materials) were produced by a top-down methodology from graphene oxide treated with ultrasounds. Graphene oxides were studied employing atomic force microscopy (AFM) to determinate the most significant parameters regarding the final size of the graphene oxide flakes during and after ultrasound treatments. GQDs were obtained by controlling the previously studied parameters and they were tested successfully as a chemicaluminiscence sensors together with Drop Sense company. Those graphene materials obtained from pregraphitic materials (cokes) were employed to understand the influence of the raw material’s nature by studying their electrical conductivity. Mesophase pitch (another type of pregraphitic material) was used for the first time as a raw material to obtain graphene materials. 2D architectures were formed onto Si, high oriented pyrolytic graphite (HOPG) and carbon fibers by two methodologies. Drop-casting was used to determine the effect of the thermal treatment of the graphene oxide flakes. This methodology allowed to modify graphite substrate electrodes with novel graphene materials supported rhodium N-Heterocyclic carbene complexes working as efficient water oxidation catalysts together with ICQSH -CSIC and the university of Zaragoza. While the EPD methodology allowed to control and study the parameters which were involved in the film growth mechanism. 3D architectures were obtained through layer-by-layer deposition methodology using GO and CNT suspensions. GO membranes were thermally treated and they were tested as cellular epitalial scaffolds together with Instituto Oftalmológico Fernéndez Vega. Hybrid membrane from GO and CNT were formed as sandwich-type structures along with the University of Oxford and they displayed a higher elasticity than pure GO membranes.