The influence of TiO2 amount on the photoactivity response for the novel TiO2/BDD/carbon fiber ternary composite

Autor: Dalva Alves de Lima Almeida, Andrea Boldarini Couto, Lânia Auxiliadora Pereira, Neidenêi Gomes Ferreira
Rok vydání: 2017
Předmět:
Zdroj: Diamond and Related Materials. 75:18-24
ISSN: 0925-9635
DOI: 10.1016/j.diamond.2016.12.018
Popis: Titanium dioxide (TiO2) deposition was studied from an electrochemical process producing binary TiO2/CF (carbon fiber) and ternary TiO2/BDD/CF (boron doped diamond/carbon fiber) composites. Emphasis was given to control de TiO2 amount as a function of the deposition time for both binary and ternary composites, which influences the photoactivity responses. TiO2 deposits were obtained by anodic hydrolysis of TiCl3 under potentiostatic mode at different deposition times, whereas BDD films were grown on CF by hot filament chemical vapor technique with high quality and crystallinity. Both composite materials were characterized by field emission gun-scanning electron microscopy (FEG-SEM) images, Raman spectroscopy, photoelectron X-ray spectroscopy (XPS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and photoelectrochemical response. FEG-SEM images depicted that the TiO2 coating homogeneities increased as the time deposition increased showing singular morphologies for both composites. The binary/ternary electrodes showed the controlled TiO2 anatase formation characterized by Raman and XPS spectra. The specific electrochemical surface area (SESA) was evaluated, from CV measurements, for all samples studied. SESA behavior associated with charge transfer resistance (Rct) values, evaluated from EIS, showed a great coherence for the photoactivity responses also correlated with FEG-SEM images.
Databáze: OpenAIRE