In Situ Deposition of Reduced Graphene Oxide on Ti Foil by a Facile, Microwave-Assisted Hydrothermal Method

Abstract

Reduced graphene oxide (rGO) was successfully deposited in situ onto Ti foil via a microwave-assisted hydrothermal method for the development of Ti-TiO2-rGO composite structures. The TiO2 crystallin layer was produced by the thermal oxidation of titanium foil in the presence of 0.5 M hydrofluoric acid in a controlled atmosphere consisting of a mixed flow gas of Ar and O2 at 500 °C. A great advantage of using the microwave-assisted hydrothermal method for obtaining composite structures is the fast and uniform heating mode, which prevents the aggregation of graphene layers. Specific analyses, such as X-ray diffraction, UV-VIS analysis, and SEM morphology, were used to investigate the structural, optical, and morphological characteristics of the composites. The I-V measurements of the Ti-TiO2-rGO composite structures were performed using forward bias with an applied voltage between −3 V and +3 V and a step rate of 10 mV/s. Moreover, the electrochemical behavior was obtained by cyclic voltammetry in a 1 M KNO3 supporting electrolyte and in the presence of 4 mM K3Fe(CN)6 to determine the electroactive surface area and apparent diffusion coefficient. The charge transfer resistance was investigated via electrochemical impedance spectroscopy (EIS) in a 0.1 M Na2SO4 supporting electrolyte and within a frequency range of 100 kHz to 0.1 Hz to confirm the role of rGO on the electrode’s surface. This study provided new insights into the development of high-performance and cost-effective Ti-TiO2-rGO structures both for the development of electrochemical electrodes and gas sensors.

One-Step Microwave-Assisted Hydrothermal Preparation of Zn-ZnO(Nw)-rGO Electrodes for Supercapacitor Applications

“…Ruiqi Gang et al developed an easy one-step microwave-assisted gram-scale synthesis strategy to obtain 2D/2D ZnO/rGO hybrid photocatalysts that enhanced the photocatalytic activity of tetracycline photodegradation under ultraviolet light irradiation [ 31 ]. Other structures have been developed using the microwave-assisted hydrothermal method; namely, C. Lazau et al successfully deposited rGO on titanium foil, obtaining Ti-TiO 2 -rGO composite structures suitable for electrochemical application [ 32 ]. The progress and novelty of this work consisted of the development of new hybrid electrodes based on metallic zinc decorated with nanowires of crystalline zinc oxide functionalized with reduced graphene oxide, directly in situ by microwave-assisted hydrothermal method.…”

High Gas Response Performance Based on Reduced Graphene Oxide/SnO2 Nanowires Heterostructure for Triethylamine Detection

“…Owing to the great demands of the chemical industry and real-time gas monitoring systems, high sensitivity and good stability of gas sensors are attracting tremendous attention. SnO 2 , ZnO, and WO 3 have always been the traditional and dominant materials for sensor fabrication [1][2][3][4][5][6]. However, the excellent stability, long-cycles, and low detection limit of the sensors still face the challenge, especially working at a high temperature above 200 • C. At higher temperatures, the inevitable grain growth of materials would degrade the sensor stability and life [6].…”