Synthesis And Applications Of Carbon Nanomaterial-based Nanocomposites

Several allotropes of carbon can be found in nature such as graphite, diamond and amorphous carbon. The physical and chemical properties of them greatly depend on their crystalline structures. In the past decades researchers have paid tremendous attention to carbon nanomaterials including zero-dimensional fullerene, one-dimensional carbon nanotube and two-dimensional graphene because of their good stability, high electrical conductivity, great strength and large specific surface area. So far, carbon nanomaterials have already been widely applied in biological science, electronics, energy and environmental science.Composite materials consist of two or more materials. Generally, a composite material can combine the advantages of each component to provide unique properties. Although fullerene, carbon nanotube and graphene have excellent mechanical, physical and chemical properties, the practical application of a single carbon nanomaterial may still be limited by its intrinsic characteristics. In order to broaden the application of carbon nanomaterials, the combination of them with other materials has been fueled up in recent years.To explore the potentials of carbon nanomaterials-based nanocomposites in electrochemical sensor and photocatalysis, we prepared reduced graphene oxide (RGO)-ferrocene (Fc) nanocomposites and used them to develop a glucose sensor. We also synthesized fluffy-ball-shaped carbon nanotube-TiO2 nanorod nanocomposites and graphene-51 P25 nanoparticle nanocomposites (RGO-P25) and investigated photocatalytic capabilities. The detailed information is as follows:1. Ferrocene-functionalized reduced graphene oxide for sensitive electrochemical detection of glucose. Fc-functionalized reduced graphene oxide (RGO) was associated with chitosan and glucose oxidase (GOD) to prepare a nanocomposite for glucose sensing. Scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible spectrometry and energy dispersive spectrometry were carried out to verify the formation of the nanocomposites. The gold electrode modified with the nanocomposites demonstrates high sensitivity, good specificity, a wide dynamic range and a low detection limit for glucose sensing. The real human serum sample measurement indicates that the performance of the prepared glucose sensor is comparable to the commercial available one.2. Fluffy-ball-shaped carbon nanotube-TiO2 nanorod nanocomposites for photocatalytic degradation of methylene blue. We fabricated fluffy-ball-shaped CNT-TiO2 nanorod nanocomposites via a facile hydrothermal approach. By using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it is found that the morphologies of the nanocomposites could be controlled by changing the reaction duration, CNT amount and Ti source concentration. TEM images and X-ray powder diffraction (XRD) results show the excellent crystalline structure and the rutile phase of the TiO2 nanorod in the nanocomposites. Based on the results, the growth mechanism of the CNT-TiO2 microspheres was proposed. Great potentials of the composited microspheres in water treatment were demonstrated through the photocatalytic degradation of methylene blue, in which a degradation efficiency as high as 93% could be obtained.3. Synthesis of reduced graphene oxide-TiO2 P25 nanoparticles nanocomposites for photocatalytic degradation of formaldehyde. The TiO2 P25 nanoparticles and graphene oxide were mixed together in an aqueous solution containing hydrazine hydrate and ascorbic acid. After 30-min ultrasonication and an 8-hour reaction at room temperature, RGO-P25 nanocomposites were prepared successfully. The nanocomposites were characterized with field emission scanning electron microscope. It is found that they are three-dimensional structure with P25 nanoparticles uniformly distributed on the reduce graphene oxide nanosheets. The nanocomposite is expected to be used for degradation of the formaldehyde gas under UV irradiation.