Preparation Of Polyimide/Carbon Nanomaterial Modified Electrode And Its Applications In Photoelectrocatalysis And Sensor

Developing new-style electrodes is of important scientific significance for the fabrication of electrochemical sensors and expansion of energy electrode materials. In this dissertation, several modified electrodes were prepared based on polyimide（PI）and carbon nanotube（CNT）. Electrodeposition was used to prepare nanomaterials on the PI/CNT electrode, such as MoS₂, Ni（OH）₂, etc. Several techniques were used to study the structure, morphology and property, such as scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, X-ray powder diffraction（XRD）,X-Ray photoelectron spectroscopy（XPS）, linear sweep voltammetry（LSV）, cyclic voltammetry（CV）, etc. The applications of the elecreodes in photoelectrocatalysis and sensor were studied. Details of the dissertation were as follows:1. Electrodeposition of Ni（OH）₂ on the PI/CNT electrode and study of its sensing property for glucoseNi（OH）₂ was prepared on the PI/CNT electrode by electrodeposition. SEM and TEM characterized the morphology and crystal structure of Ni（OH）₂. XPS confirmed the chemical states of elements on the PI/CNT electrode. CV study revealed large current response of PI/CNT-Ni（OH）₂ electrode towards glucose. The glucose sensor of PI/CNT-Ni（OH）₂ electrode displayed a linear range of 1.0-800 mM, a sensitivity of2071.5 mA m M-1 cm-2, a detection limit of 0.36 mM, good reproducibility and stability.The glucose sensor was used to detect glucose in human blood serum samples.2. Electrodeposition of In modified Zn O on the PI/CNT electrode and study of its application in catechol sensorZn O nanosheets were first prepared on the PI/CNT electrode, and then In nanoparticles were electrodeposited on the PI/CNT-Zn O electrode. CV studied the electrocatalytic activity of the PI/CNT-Zn O electrode towards CC. In nanoparticles improved the electrocatalytic activity and the PI/CNT-Zn O electrodes with differentcontents of In showed different properties. The CC sensor of PI/CNT-Zn O-In（3.79%）electrode had rapid current response, an linear range of 1.0-1600 mM, a detection limit of 0.39 mM, good stability and anti-interference. The sensor had good application in the detection of CC in practical water samples.3. Electrodeposition of MoS₂ on reduced graphene oxide-modified PI/CNT electrode and study of its electrocatalytic activity for hydrogen evolution reactionDuring the synthesis of PI/CNT electrode, high-conductive CNT was added into non-conductive PI to obtain conductive electrode of PI/CNT. RGO further improved the conductivity of PI/CNT electrode and magnified the electrode surface area. MoS₂ was electrodeposited on the PI/CNT electrode. LSV studied the HER activity of the PI/CNT-RGO-MoS₂ electrode, revealing the overpotential of 0.09 V（vs. SCE） and rapid increase of current in 0.5 M H2SO4. Tafel slope of 61 m V decade-1 indicated the Volmer-Heyrovsky mechanism in the HER on the PI/CNT-RGO-MoS₂ electrode.4. Electrodeposition of Co（OH）₂ on the PI/CNT electrode and study of its electrocatalytic activity for oxygen evolution reactionCo（OH）₂ was electrodeposited on the PI/CNT electrode. SEM and TEM showed the morphology and crystal structure of Co（OH）₂. LSV studied the OER activity of the PI/CNT-Co（OH）₂ electrode in alkaline solution, which afforded an overpotential of 0.317 V（vs. SCE）, Tafel slope of 49 m V/decade and rapid increase of OER current.The high OER electrocatalytic activity was mainly attributed to large ECSA of the Co（OH）₂ nanosheets on the PI/CNT electrode.5. Electrodeposition of semiconductor ZnTe on the PI/CNT electrode and study of its photoelectrical propertyCV studied the electrochemical characteristics of H2 Te O3 and Zn SO4 on the PI/CNT electrode. The preparation of ZnTe was performed by alternate deposition of Te and Zn. SEM and TEM showed well-defined dendritic structure of ZnTe, which was greatly affected by the concentration of reagents and deposition cycle. OCP-time experiments were carried out to study the photoelectrical property of ZnTe, which indicated that ZnTe on the PI/CNT electrode was a p-type semiconductor and had good photoelectrical property.