Synthesis Of New-style Modified Electrode Based On Metal Hexacyanoferrate And Its Application In The Detection Of N₂H₄

Hydrazine(N2H4·H2O)and its derivatives have been found to have wide applications in industry,agriculture,explosives,antioxidants,photographic developer,oxygen scavengers and propellants.But hydrazine has been recognized as a carcinogenic and hepatotoxic substance,which causes liver and kidney damages.All the above traits make their detection and quantitation problems of considerable importance in agriculture,industry,explosives and pharmaceutical industry.The transition metal hexacyanoferrates has a great application potential for the electrocatalytic of hydrazine and the electrode modification.In this paper,we synthesized three modified electrodes with Prussian blue or Prussian blue analogue and utilized the sensors for hydrazine.The main work is as follow:1.We prepared a triple-component modified electrode(PB@Ag/GF)fabricated by freestanding Graphite felt(GF),silver nanoparticles(Ag)and Prussian blue(PB).The electrode was confirmed by various techniques such as scanning election microscope(SEM),infrared spectroscopy(FI-IR),X-ray diffraction(XRD),and energy-dispersive X-ray spectroscopy(EDS),respectively.The electrochemical behavior of PB@Ag/GF was measured by cyclic voltammetry,which exhibits two pairs of well-defined redox peaks,attributed to Prussian blue/Prussian white and Prussian blue/Berlin green redox process.The influence of GF preparation,the type and the concentrations of electrolyte,the voltage and time of deponsition were studied.The electrode was displayed a prominent electrocatalytic activity toward hydrazine oxidation,with a low response time of 2 s,a low detection limit of 4.9 × 10-7 M and very high detection sensitivity of 26.06 A·cm-2·M-1,with a signal to noise ratio of 3.The sensor also has a good stability and selectivity.2.Mn-Fe PBA was synthesized in water-in-oil bis(2-ethylhexyl)sodium sulfosuccinate(AOT)reverse microemulsions and Ag-CNTs was parpared by chemical reduction method,respectively.And then a composite materials(Mn-Fe PBA/Ag-CNTs)was fabricated by mixing Mn-Fe PBA and Ag-CNTs ultrasonically.The composite materials was confirmed by various techniques such as TEM,FI-IR,XRD,and EDS,respectively.Cyclic voltammetric measurements on glass carbon electrode showed that the composite materials exhibits a well-defined pair of redox peaks.The influence of the type and the concentrations of electrolyte,dispensing volume were studied.It was found that the electrode showed a prominent electrocatalytic activity toward hydrazine oxidation.The sensor has a linear response to hydrazine concentration ranging from 4.1 × 10-6 to 1.80 × 10-3 M,with a low detection limit of 1.5 × 10-6 M and very high detection sensitivity of 5.56 A·cm-2·M-1,respectively.The triple-component sensor has a fast response time blow 2 s,with a signal to noise ratio of 3.3.We synthesized cobalt hexacyanoferrate nanoparticles(Co-Fe PBA)in water-in-oil bis(2-ethylhexyl)sodium sulfosuccinate(AOT)reverse microemulsions and Ag-CNTs was parpared by chemical reduction method,respectively.Then,a composite materials(Co-Fe PBA/Ag-CNTs)was fabricated by mixing Co-Fe PBA and Ag-CNTs ultrasonically.The composite materials was confirmed by various techniques such as SEM,TEM,FI-IR,and EDS,respectively.Cyclic voltammetric measurements on glass carbon electrode showed that the composite materials exhibits a well-defined pair of redox peaks.The influence of the type and the concentrations of electrolyte,pH values,and dispensing volume were studied.The results indicated that the electrode also showed electrocatalytic activity toward hydrazine oxidation.The electrode has a low response time of 2 s,a detection limit of 4.7 × 10-6 M and a detection sensitivity of 3.961 A·cm-2·M-1,respectively,with a signal to noise ratio of 3.