| In this dissertation the multiwalled carbon nanotubes(MWNTs) were prepared by mechanical ball milling and acidification, and characterized with the transmission electron microscopy(TEM), infrared spectroscopy(IR), X-ray diffraction(XRD) and thermogravimetric analysis(TGA). The polyvinyl alcohol/ethanol(v/v=1:1)solution was used to disperse MWNTs, and then developed a novel carbon nanotubes/PVA membrane modified electrode. Cyclicvoltametry(CV),electrochemical impedance spectru(EIS), chronoamperometry(CA) and different pulse voltammogram(DPV) were used to study the electrochemical behaviors of the modified electrode and hydroquinone. The proposed modified electrode was directly used to determine hydroquinone in simulation developer.The results of transmission electron microscopy (TEM) indicated that the length of MWNTs became shorter and the defects on surface increased with increasing milling time. Experimentation also revealed that mechanical ball milling and acid treatment not only could purify carbon nanotubes, increase the degree of purity and graphitization, but also could introduce carbonyl groups on the surface of MWNTs. The carbon nanotubes can be suspended homogeneously in polyvinyl alcohol/alcohol solution.The electrochemical activities of MWNTs modified electrode in K3[Fe(CN)6] were investigated by using cyclic voltametry(CV), electrochemical impedance spectru(EIS) and chronoamperometry(CA). CV showed that the oxidation peak current Ipa of 5h milled MWNTs modified electrode was 18.53μA, which increased more than about 50% compared with that of original MWNTs modified electrode (12.50μA). EIS and CA indicated that the shorter MWNTs could effectively promote the diffusion and electron transfer of electroactive substance.In the study of hydroquinone, the 0.1mol/L phosphate buffer solution as supporting electrolyte was determined by experimentation, and the pH value of the phosphate buffer solution was selected to be 6.0. When pH=4.0~9.1, the formal potential of hydroquinone E0(E0=[Epa+Epc]/2)had a linear relation with the pH value, linear regression equation was E0=(-53.62pH+761.42) mV, R2 =0.9486, with a slope of 53.62. The result showed that the number of electrons transferred was equal to the amount of hydrogen ion participating in electrode reaction. Ipa =(6.5344v1/2-9.7406)uA, R2=0.9994, which indicated that the redox process was diffusion-controlled. The dissertation proposed method could directly determine the amounts of hydroquinone using MWNTs/PVA membrane modified electrode as working elelctrode, based on the relationship between the oxidation peak currents of cyclic voltametry and different pulse voltammogram with hydroquinone concentration. The cyclic voltametry showed linear response over the hydroquinone concentration range was from 8.0×10-5 mol/L ~ 2.0×10-3 mol/L, linear regression equation was y= 0.026x+32.433, R2=0.9872, and the detection limit (3σ)being 9.5×10-6 mol/L. Different pulse voltammogram revaeled linear response over the hydroquinone concentration range was from 5.0×10-5mol/L ~1.0×10-3mol/L, linear regression equation was y=0.026x+21.691, R2=0.9980, and the detection limit (3σ) being 1.5×10-6 mol/L. When studied the influence of those co-existing ions on the determination of hydroquinone in nature water samples, it was found that all the studied co-existing substances could be tolerated in considerable amounts. Therefore, the proposed method has been directly used for determining the amounts of hydroquinone in photographic waste water. Standard addition method was used for the determination of hydroquinone in simulated water samples with satisfactory results.
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