Studies On The Electrochemical Properties Of Prussian Blue Composite Electrode And Prussian Blue Analogue Modified By Plasma

At present,food safety issues have received more attention,so it is particularly important to detect biomolecules.On the other hand,because of the increasingly severe energy shortage and environmental pollution,researchers have focused on sustainable and clean energy,especially hydrogen and oxygen produced by electrolyzed water.Due to the advantages of simple preparation,low cost and wide source,transition metal cyanide with open frame is often used as a precursor for electrochemical analysis and OER reaction electrode materials.Therefore,in this paper,an electrochemical sensor based on Prussian blue（PB）composite material was synthesized and applied for detection of dopamine.Subsequently,we synthesized nickel-based Prussian blue analogue and loaded it on nickel foam（NiFe PBA/NF）.Then the sample was irradiated with nitrogen/oxygen（N₂/O₂）plasma and the obtained composite electrode was utilized for OER reaction.Finally,CoCo PBA anchored on graphite felt（GF）was irradiated with argon（Ar）plasma,the composite electrode was used to detect ascorbic acid（AA）.1.A composite of N,P-doped molybdenum carbide and PB was synthesized and anchored on graphite felt（GF）to obtain Prussian blue/molybdenum carbide/graphite felt composite electrode（N,P-Mo₂C/PB/GF）.The scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）,elemental analysis（EDS）,X-ray photoelectron spectroscopy（XPS）and some electrochemical tests were conducted on the electrode materials,respectively.Besides,the UV-visible spectrophotometry was used to prove the promotion of N,P-doped molybdenum carbide（N,P-Mo₂C）nanospheres on the synthesis of PB.Finally,the composite electrode was utilized for determination of dopamine.The results show that the as-prepared sensor presents excellent performance with a lower detection limit（0.014μM）,a wider detection range（0.18-30μM,30-280μM）and a higher sensitivity（0.268 A·M,0.045 A·M）,besides,a satisfactory result was obtained in the real sample detection process..2.NiFe PBA was loaded on nickel foam（NiFe PBA/NF）by ultrasound,and then a series of composite electrodes were got by being irradiated by different plasma sources（Ar,O₂,N₂ and N₂/O₂）.The as-prepared composite electrode was characterized by SEM,TEM,XRD,Mapping,XPS and electrochemical tests,respectively.The results prove that the electrocatalytic effect of the the sample irradiated with N₂/O₂plasma was enhanced to a greater extent by generating vacancy defects and forming metal oxides,so N₂/O₂-NiFe PBA/NF has a lower overpotential and a smaller Tafel slope at 10 mA·cm^-2 in alkaline electrolyte.3.In addition to applying plasma technology in the field of OER,we also explored the application of plasma surface modification in the detection of biomolecules.First,CoCo PBA was prepared by co-precipitation method and was loaded on graphite felt（GF）,then the composite materials were irradiated with N₂,O₂ and Ar plasma,respectively.It is found that the current response of CoCo PBA after Ar plasma modification is the most significant when the electrode was used to detect AA,due to the increased surface roughness of the material and more ion diffussion channels.Thereafter,the as-synthesized Ar-CoCo PBA was characterized by SEM,TEM,XRD and FTIR,respectively.And composite electrode Ar-CoCo PBA/GF was applied to detect ascorbic acid（AA）.It is shown that the sensor has a detection limit of 0.25μM,a detection range of 2.39-617μM,and a sensitivity of 0.35 A·M.