Fabrication Of Prussian Blue/CNTs Modified Electrode And The Study Of Its Performance

The PB/WMNTs modified electrode was fabricated through sequential deposition method in which MWNTs was sequentially immerged into deposition solution containing Fe³⁺ and [Fe(CN)₆]^4-. Concentration of deposition solution, deposition cycles and deposition time were investigated to examine their effect on the properties of electrode. SEM, FTIR, XPS and XRD were used to characterize the electrode, and the modified electrode was used to analyze hydrogen peroxide. The application of sequential deposition method was branched out to prepare NiHCF/MWNTs, CoHCF/MWNTs and PB/active carbon.The physical characterization indicates that PB/MWNTs modified electrode can be successfully fabricated through sequential deposition. The depositon solution concentration of 1×10^-3 mol·L^-1, deposition cycles of 3, and deposition time of 30 minutes are the optimal preparation condition. Under this condition, the diameter of PB crystal is about 10 nm with orientation to (200). The mechanism of sequential deposition is as follows: Once the adsorbed Fe³⁺ reacts with [Fe(CN)₆]^4- the formed unstoichiometric precipitation of Fe_x[Fe(CN)₆]_y deposits on the interlayer of MWNTs. Since the unstoichiometric precipitation keeps active sites of C≡N groups with which Fe³⁺ would further react and more PB would be produced after several deposition cycles.The related experiment conditions for measuring H₂O₂ and the electrochemical characteristics of cyclic voltammetry (CV) were studied in detail. The optimum conditions are pH = 5.6 and C(K⁺) = 0.2 mol·L^-1 with a scan rate of 50 mV·s^-1. Study results demonstrate that the modified electrode is stable and applicable in electrochemistry analysis.Through comparison of GC, MWNTs/GC and PB/MWNTs/GC modified electrode, it can be found that PB/MWNTs/GC shows good electrocatalysis on the reduction of hydrogen peroxide, leading higher peak current on the CV curve. The reductive peaks current of the fabricated PB/MWNTs/GC electrode is proportional to the concentration of H₂O₂ in the range of 8.0×10^-5 mol·L^-1-1.0×10^-3 mol·L^-1 with 99.37% recovery.