Preparation Of Micro-nano Carbon Materials Modified Electrodes And Its Electrochemical Performance

A chemically modified electrodes (CMEs) is an electrical conductor that has its surface modified by a molecular monolayer or perhaps a few micrometers-thick multilayer of a selected chemical bonded to or coated on the electrode surface to endow the electrode with the chemical, electrochemical, optical, electrical, transport, and other desirable properties of the film in a rational, chemically designed manner. Chemically modified electrodes (CMEs) comprise a relatively modern approach to electrode systems that finds utility in a wide spectrum of basic electrochemical investigations, including the relationship of heterogeneous electron transfer and chemical reactivity to electrode surface chemistry, electrostatic phenomena at electrode surfaces, and electron and ionic transport phenomena in polymers. The design of electrochemical devices and systems has a wide range of potential applications in chemical sensing, energy conversion and storage, molecular electronics, electrochromic displays, corrosion protection, and electro-organic syntheses.In this work, arc discharge was adopted to prepare diamond-like carbon thin film modified graphite electrodes, chemical vapor deposition (CVD) was employed to in situ synthesize Ni/C core-shell structure modified graphite electrodes and graphene-like carbon thin film electrode on quartz respectively, and the electrochemical performance of these prepared electrodes were also investigated. The details are as follows:(1) Diamond-like carbon thin films (DLC) were prepared by Arc Discharge. The electrochemical performance of the prepared electrodes at conditions with varying discharge currents and discharge time were investigated in the detection solution containing Fe(CN)63-/4-ions, and the morphology of DLC thin films was characterized by FESEM. The results showed that at argon atmosphere with a constant pressure of1.0×104Pa, the DLC modified electrode prepared with the discharge current of80A and the discharge time of1.5min had relatively better electrochemical performance than that of others prepared at different conditions, and the DLC thin film was comprised of carbon particles with microns diameter.(2) Nickel/carbon core-shell structure with uniform diameter has been synthesized by galvanostatic electrodeposition nickel on its surface followed by chemical vapor deposition. The substrate with deposited nickel was characterized by optical microscope. The crystalline features of the deposited nickel film before and after annealing were characterized by X-ray diffraction (XRD), the morphology and electrochemical performance of the Ni/C core-shell structure were characterized by FESEM and Cyclic voltammetry (CV), respectively. The results showed that the nickel/carbon core-shell structure has an average diameter of250nm and demonstrated pretty well electrochemical property. We believed the mechanism for the formation of the core-shell structure is closely related to the size of nickel particles, larger nickel particles leading to the formation of the core-shell structure, while smaller particles leading to the formation of carbon nanotubes (CNTs).(3) Direct preparation of graphene-like thin films on quartz glasses was demonstrated by ambient pressure chemical vapor deposition without the assistance of metal catalysts. By investigating the electrical performances, conditions with the growth temperature at900℃H2and C2H2feeding rate at50sccm and5sccm respectively were established to synthesize graphene-like thin films with excellent conductivity. The as-synthesized thin films were characterized by XRD, UV-vis spectroscope, Raman spectroscope and FESEM. The results showed that the as-synthesized thin films with clear layer structures were non-crystalline material, and possessed excellent electrochemical performance in the detection solution, indicating its prospective applications in electrochemistry and electronics, etc.