Discussion On The Side Reaction In The Reaction Of Electrocatalytic Reduction Of H₂O₂ By Prussian Blue Modified Electrode

This article mainly studies the electrochemical response signals of catalytic reduction of H₂O₂ by the PB modified electrodes which prepared by FeCl₃?K₃Fe?CN?₆ with different proportion and their difference.And discuss the electrochemical responses of FeCl₃?K₃Fe?CN?₆ to H₂O₂ at different scan rate were studied respectively in a neutral environment,in order to research the effect of the adsorbed ions on the surface of PB modified electrode catalytic reduction of H₂O₂.Through the experiment we found,under the condition of high scan rate,the catalytic behavior of the adsorbed ions on the surface of PB modified electrode to H₂O₂ is dominant;Under the condition of low scan rate,the main reaction of PB electrochemical catalytic reduction of H₂O₂ is dominant.In the neutral environment,through the experiment we can learn that the electrochemical catalytic reduction of Fe?CN?₆^3-to H₂O₂,which is not only related to the scan rate,but also to the p H of the solution.It is also proved that Fe?CN?₆^3-does not inhibit the catalytic reduction of H₂O₂ in fact,Instead,under the different conditions,it performs different signals with the main and side reactions dominate the different.On the other hand,we also prepared the PB-Ppy composite electrode,cyclic voltammetry study showed that the electrode has a certain p H stability.In order to further improve the sensitivity of the electrode response to H₂O₂,MWNTs was used to prepare the PB-Ppy/MWNTs composite electrode.Differential pulse voltammetry?DPV?technique was applied to study the electrochemical response of PB-Ppy/MWNTs electrode to H₂O₂.The experimental results showed that the PB-Ppy/MWNTs electrode has a good linear response for H₂O₂ in range of25.2⁵0.4 ?mol/L and in 175¹400 ?mol/L.PB-Ppy?Fe?/PVA composite electrode prepared by Fe³⁺ with the different proportion of excess,observed the effect of it catalytic reduction of H₂O₂.Through the experiment we found that the PB modified electrode prepared whether or not combined with other substances,the catalytic effects are related to the ratio of Fe³⁺?Fe?CN?₆^3-and the side reaction brought.In order to further research the mechanism of catalytic reduction of H₂O₂ by PB and the side reaction,and study to promote the catalytic reaction of the composite electrode prepared by mixing PB with other substances,which provide the basis to prepare high efficiency and accuracy of PB sensors in the future.