Preparation Of Graphene Functional Polyimide Flexible Modified Electrode And Its Application In Sensor And Photovoltaic Conversion

Modified film electrodes based polimide ?PI? have good chemical stability and machinability,so attracting more and more attention in photoelectric device. In this thesis, we prepared reduced oxide graphene ?rGO?/PI flexible film electrode, and various nanometer semiconductor materials were modified on rGO/PI flexible substrate. Several chemical and physical analysis methods were proposed to study the structure, morphology and properties of modifiled film electrode, such as scanning electron microscope ?SEM?, transition electronic microscope ?TEM?, X-ray photoelectron spectroscopy?XPS?, X-ray polycrystalline diffractometer ?XRD?, cyclic voltammeter?CV?, linear sweep voltammetry?LSV?, differential pulse voltammeter ?DPV?, open circuit potential -time ?OCP -t? and so on. The applications of modified film electrodes in sensor and photovoltaic conversion were studied. The main contents of the thesis were as follows:1. A novel dopamine sensor based on Mo doped reduced graphene oxide/polyimide composite membraneA novel Mo doped reduced graphene oxide/polyimide ?Mo-rGO/PI? composite membrane sensor for dopamine ?DA? has been successfully prepared by a simple and effective method. The combined characterization by XPS and XRD indicated that Mo existed in rGO/PI film in the form of MoO2. Under optimal conditions, the Mo doped rGO/PI film exhibited excellent catalytic activity to DA by LSV,with a linear range of 0.1 - 2000 mM,a detection limit of 0.021 uM?S/N=3?, it also showed long-term stability, good reproducibility and anti-interference, and performed well for detection of DA in human blood serums and injection.2. Fabrication of Acetylcholinesterase modified Au-MoS2-rGO/PI flexible film biosensor and it's application in detection of paraoxonAuNPs were prepared on MoS-2-rGO/PI flexible film electrode by photo-reduction method,TEM characterized the structure of AuNPs with just 10 nm in diameter. DPV displayed acetylcholinesterase modified Au-MoS2-rGO/PI flexible film electrode had large current response toward acetylcholine chloride, and showed a linearity range of 0.005-0.15 ug/mL for paraoxon, a sensitivity of 4.44 uA/ug mL-1, a detection limit of 0.0014ug/mL, good stability and repeatability.The flexible film biosensor can be used to detect organophosphorus pesticide in real samples.3. Electrodeposition of MoSe₂ on the rGO/PI film electrode and study of its electrocatalysis and photoelectrocatalysis activity for hydrogen evolutionMoSe₂ was synthesized on rGO/PI substrate by a simple electrochemical method, the XRD?XPS?SEM and TEM were conducted to confirm it's morphology and structure. The MoSe₂-rGO/PI composite film electrode had excellent photo-responsive properties; the potential difference could reach 0.45 V, photocurrent response time was within 0.6 s. Furthermore, MoSe₂ thin film exhibited superior catalytic activity in the hydrogen evolution reaction ?HER? by LSV,revealing 7.9 mA cm-2 at the overpotential of 0.3 V. Besides, combined HER performance with photoelectric property, finding illumination can effectively promote HER activity of MoSe₂.4. Electrochemical deposition of diluted magnetic semiconductor ZnMnSe₂ on reduced graphene oxide/polyimide substrate and its propertiesDiluted magnetic semiconductor ZnMnSe₂ was synthesized on reduced graphene oxide/polyimide ?rGO/PI? substrate by a simple electrochemical method, the SEM displayed ZnMnSe₂ has specific porous structure that was consisted of nanosheets. OCP indicated that ZnMnSe₂ composite film had good optoelectronic property with the potential difference 270 mV,which was more than ZnSe and MnSe. Besides, the ZnMnSe₂ composite film had prominent magnetism, and it was ferromagnetism material.5. Electrochemical deposition semiconductor ZnSe on a new substrate CNTs/PVA and its photoelectrical propertiesZnSe composite film was prepared by i-t alternate deposition of Zn and Se based on new flexible film electrode CNTs/PVA. By controlling concentrations of Zn and Se, It can be observed that the morphology changed with the different proportion of Zn/Se by SEM, and when the ratio of Zn/Se was close to one, the surface morphology was consist of most regular and uniformity nanorods. OCP- time indicated that ZnxSe1-x ?x = 0.3, 0.5, 0.67? films had good p-type properties,three kinds of photoelectrical phenomena were observed, but the photoelectrical property of ZnSe was the best and most disciplinary in all films.