Application Of Graphene-based Inorganic Composites In Electroanalysis And Supercapacitors

In this paper,the high specific surface of graphene and the high catalytic activity of inorganic nanoparticles were used to synthesize graphene-based inorganic nanocomposites with synergistic enhancement effect by a facile solvothermal method.Morphological structure of the products were characterized by Scanning electron microscopy,Transmission electron microscope,Raman spectrum and X-ray powder diffraction（XRD）;Graphene-based inorganic nanocomposites were used in the construction of electrochemical sensors and supercapacitors,respectively,which can be used for high sensitivity detection of active ingredient Rutin of Chinese medicine,environmental hormone Hydroquinone（HQ）,Catechol（CA）and research on the performance of electric double layer capacitor（EDLC）.The experiment results show that the electrochemical sensor constructed by Graphene-based inorganic nanocomposites has high sensitivity,excellent selectivity and outstanding stability,The electric double layer capacitor has high specific capacitance,rapid charge and discharge rate and long cycle life.The main contents of this paper are as follows:1.MoCl₅ can be controllable transformed into nanosphere-MoO₃ in hydrothermal reaction.MoO₃ has good electrocatalysis for phenolic substances.MoCl₅ and graphene oxide（GO）were used to synthesize graphene-based molybdenum oxide nanocomposites（MoO₃-RGO）through the facile solvothermal reaction in anhydrous ethanol medium.MoO₃-RGO modified glassy carbon electrode（MoO₃-RGO/GCE）was used for the simultaneous detection of HQ and CA,The peak current intensity,detection limit and linear relationship were significantly better than those of unmodified glassy carbon electrodes.Under the optimal experimental conditions,MoO₃-RGO/GCE can complete the simultaneous detection of HQ and CA satisfactorily.2.GO was dispersed by ultrasonic in mixed solvent contenting of different volume ratios of absolute ethanol and cyclohexanol.NbCl₅ was dissolved in absolute ethanol and mixed with GO dispersion fully.The reaction was carried out in a muffle furnace at 235°C for 72h.Graphene-based antimony pentoxide nanocomposites（Nb₂O₅-RGO）was characterized by SEM,XRD,Raman and other characterization techniques.The electrochemical behavior of Rutin on Nb₂O₅-RGO/GCE was studied systematically.Under the optimized conditions,the linear relationship of Rutin concentrationintherangeof0-50μMonNb₂O₅-RGO/GCEwas I_Pa（μA）=0.72854C（μM）+4.985,R=0.9963,detection limit D=8.7×10^-9M（S/N=3）.The Rutin content in the actual drug was determined by Nb₂O₅-RGO/GCE and the recovery values were between 93.6%and 97.2%.3.The chain structure Chitosan has good film forming properties and biocompatibility.In the experiment,Chitosan and GO were dispersed in 1%acetic acid with silver nitrate for hydrothermal reaction.Graphene-based silver nanoparticals composite（Ag-NPs&RGO）was obtained through low temperature freeze-drying.Scanning electron microscopy shows that the Ag-NPs&RGO composite has excellent appearance and clear three dimensional skeleton.The Ag-NPs&RGO modified glassy carbon electrode（Ag-NPs&RGO/GCE）was applied to simultaneous detection of HQ and CA successfully.4.Cube-shaped In（OH）₃ has excellent capacitance performance.InCl₃ as the precursor salt and GO as carrier,Graphene-based Indium hydroxide（In（OH）₃-RGO）nanocomposites was synthesized through solvothermal in 95%ethanol medium.The cubic In（OH）₃ nanoparticals adhering to the surface of graphene effectively prevents graphene sheets from stacking and increases the specific surface of the materials.In（OH）₃-RGO promotes sufficient contact between the electrolyte and electrode interface,which promote the capacitance value of electric double layer materials.Galvanostatic charge-discharge results show that the specific capacitance of In（OH）₃-RGO was 232.3F·g^-11 at a density of 0.1 A·g^-11 and the capacitance retention rate is 94.1%after 1000 cycles.The results indicate that In（OH）₃-RGO has considerable specific capacitance values and high cycle stability.