Preparation Of Carbon Nanotube Chemaically Modified Electrodes Grown In Situ

In this thesis,grown in situ carbon nanotube chemically modified electrodes(GSCNT-CME) was prepared by the chemical vapor deposition (CVD).Preparation of GSCNT-CME via changing the ratio of catalyst and reaction gas was studied in this paper.Moreover,we also discussed the optimum condition of GSCNT-CME.1.Catalyst adhered to the surface of graphite electrode via impregnated method.At the same time,H₂,N₂ and C₂H₂ were used as the reduction gas,protection gas and carbon source gas,respectively.Growing CNTs directly on the surface of graphite was introduced in preparing GSCNT-CME.A series of La-Ni-O compounds were synthesized with modifying the mol ratio of La and Ni and changing the ratio of reaction gas.And the morphology of CNTs were characterd by SEM as well as the electrochemical properties were tested by CV.It found that the most CNTs can be achieved using lest catalyst when the ratio of nickel nitrate,lanthanum nitrate and citric acid was 1:1:4.Under this condition,CNTs with defects on the surface could be gained at the volume ratio of N₂ and C₂H₂ at 30:1.It demonstrated that GSCNT-CME with defected CNTs presented more excellent electrochemical property.It also indicated that GSCNT-CME has high stability due to the CNTs growing on the lattice of atomic carbon on the graphite electrode.2.Carbon nanotubes in situ chemically modified electrodes(CNT-CME) were prepared by CVD method.Carbon nanotubes grew on the graphite substratum,which was impregnated in catalyst solution.The electrochemical property of CNT-CME depended on the preparing condition,such as preparation conditions(catalyst pretreatment time, CNT growing time and so on.Through SEM test of CNTs and cyclic voltammetry of[Fe(CN)₆]^3-/[Fe(CN)₆]^4- redox couple solution,it found that GSCNT-CME presented excellent character when the catalyst immersing time was 6 h and the catalyst pretreated at 500℃for 5 h.Anodic peak currents of the prepared material depended linearly on the square root of the scan rate over the range of-0.83～20mV·s^-1.From this,we know the chemically modified electrode is a quasi-reversible cyclic voltammetric electrode.Thus it not only expands rang of carbon nanotubes application,but also abounds the content and the technique of electrochemical analysis.There is future for the applications of carbon nanotubes chemically modified electrode in electroanalysis.