Preparation Of Multi-component Carbon Nano Composite Materials Modified Electrode And Its Application

The investigation of theory and its application of chemically modified electrode(CMEs) are always the main reseach fields in electrochemical chemistry and electrochemical analysis. Carbon-based nano composite materials, such as graphene and carbon nanotubes, as well as carbon nano fiber are the main materials for preparation of chemically modified electrode due to their special physical and chemical properties. In order to futher enrich the application of these nano materials in electrochemical sensing field, preparation and application of a electrode modified with multi-component carbon-based composite materials such as graphene-carbon nanotubes, carbon nano material-metal nano particles and polymer have been received keen interests. Multi-component carbon nano composite materials exhibits more special properties and improve the analytical featrures of the modified electrode such as low detection limits, wide linear ranges and high sensitivities compared to single material.In this paper, three kinds of chemically modified electrode including gold nanoparticles-the reduced graphene oxide-multi-walled carbon nanotubes nano composite(Au NPs-RGO-MWCNTs), nano copper oxide-the reduced graphene oxide-multi-walled carbon nanotubes nano composite(Cu O-RGO-MWCNTs) and nano cobalt hydroxide-the reduced graphene oxide-multi-walled carbon nanotubes nano composite(Co(OH)2-RGO-MWCNTs) have been prepared using dipping method, electrochemical techniques as well as in-situ chemical reduction strategies. The electrochemical properties of these modified electrodes have been inveatigated carefully. Moreover, these modified electrode have also been used for the determination of bisphenol A, L-tyrosine and hydrogen peroxide. The main contents of this thesis are as follows:1. A gold nanoparticels-the reduced grapheme oxide-multi walled carbon nanotubes nanocomposite modified electrode(Au NPs-RGO-MWCNTs/GCE) has been fabricated by using chemical reduction and electrochemical technique. The surface morphology, electrochemical propeies as well as the electrocatalytic activity of the resulting modified electrode has been studied carefully. The results show that this modified electrode exhibited high electrochemical activity to the oxidation of bisphenol A(BPA). Under the optimum conditions, the linear range for determination of BPA with differential pulse voltammetry(DPV) is 5.0 × 10-9 to 2.0 × 10-6 mol?L-1 with a detection limit of 1.0 n M(3sb), respectively. This modified electrode has some attractive analytical features such as low detection limit, wide linear range, good reproducibility as well as simple preparation.2. A copper oxide-graphene-multi walled carbon nanotubes three-component nanocomposite modified electrode(Cu O-RGO-MWCNTs/GCE) was fabricated by two steps procedure. Firstly, the RGO-MWCNTs composite has been prepared using in-situ chemical reduction and modified on the base electrode using dipping method. Then, Cu O nanoparticles have been deposited on the electrode surface by using electrochemical method. The surface morphology, electrochemical properties as well as the electrocatalytic activity of the resulting modified electrode has been studied carefully. The results show that the electrochemical activity of this modified electrode for the reduction of hydrogen peroxide(H2O2) has been improved dut to the introduction of RGO and MWCNTs. Under the optimum conditions, the linear range for determination of hydrogen peroxide with amperometry in 0.10 mol?L-1 PBS is 5.0 × 10-6 to 1.4 × 10-2 mol?L-1 with a detection limit of 1.0 μM(3sb), respectively. This modified electrode has some attractive analytical features such as low detection limit, high sensitivity, wide linear range, as well as small interference by oxygen.3. A glass carbon electrode(GCE) was modified with a composite film composed of copper oxide, reduced graphene oxide(r GO), and multi-walled carbon nanotubes(MWCNTs) by dropping method and electrochemical method. The electrochemical behavior of L-Tyrosine(L-Tyr) has been investigated on this Cu O/RGO-MWCNTs/GCE modified electrode. The results show that this modified electrode has high electrochemical activity for the oxidation of L-Tyr due to the senergic action of Cu O, RGO and MWCNTs. Under optimum conditions, the linear range for determination of L-Tyr by amperometry is 2.0 × 10-8 ~ 1.8 × 10-4 mol?L-1, with a detection limit of 5.0 × 10-9 mol?L-1(S / N = 3), respectively. This modiifed electrode has also been used to detemine L-Tyr in a real amino acid injection(18-AA). Compared to other modified electrode based on copper material, this modified electrode has some attractive analytical features such as low detection limit, wide linear range, as well as good selectivity.4. A cobalt hydroxide-the reduced graphene oxide-overoxidized polypyrrole composite film(Co(OH)2-RGO-MWCNTs) modified electrode has been prepared by three steps procedure. Firstily, a RGO-OPpy composite film has been electrochemically deposited on the base electrode surface using graphene oxide as dopant. Then, cobalt hexacyanoferrate nanoparticles have deposited on this composite film surface by cyclic voltammetry. Lastlty, this electrode has been derived in base solution using electrochemical method and a Co(OH)2-ERGO-OPpy/CCE is obatained. The electrochemical behavior and the electrocatalytic activity for the electrochemical oxidation of hydrogen peroxide of this modified electrode were investigated carefully. The results show that this modified electrode has strongly electrocatalytic activity for the oxidation of hydrogen peroxide. In B-R buffer(p H 9.0), the liner relationship between the catalytic current and the hydrogen peroxide concentration is in the range of 2.0 × 10-7 ~ 4.9 × 10-4 mol?L-1 by using amperometric technique, the detection limit and sensitivity was( 3sb, n=11) 7.0 × 10-8 mol?L-1 and 163 μA?(mmol?L-1)-1, respectively.