A novel modified electrode was prepared by electrochemicaly cycling scanning the glass carbon electrode covered with a macroporous alumina membrane in a solution containing PPy and PMo 12O 3- 40. The reversibility of ...A novel modified electrode was prepared by electrochemicaly cycling scanning the glass carbon electrode covered with a macroporous alumina membrane in a solution containing PPy and PMo 12O 3- 40. The reversibility of the cyclic voltammograms was improved obviously. The remarkable advantage of the modified electrode was the high sensitivity and favorable electrocatalytic behavior toward NO - 2. The peak current increased linearly with the concentration of NO - 2 in the range of 8.0×10 -7—0.01 mol/L. The detection limit of NO - 2 was 1.0×10 -9 mol/L. The polyoxometalates nanopaticles modified electrode exhibited almost the same electrochemical behavior after 7 d. It is indicated that the PMo 12-PPy/AGCE has a good reproducibility, stability and wide linearity range.展开更多
A polypyrrole-modified glassy carbon electrode （PPy/GC electrode） was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry （LSV）. ...A polypyrrole-modified glassy carbon electrode （PPy/GC electrode） was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry （LSV）. A well-defined new reduction peak appeared at a more positive potential than the original reduction peak. The new reduction peak current was linearly related to the acid value （AV） of oil. Based on it, a rapid electrochemical method for determining AV of transformer oil was developed using PPy/GC electrode. A working curve was obtained in the AV range of 0.01 to 0.40 mg（KOH）.g^-1, with a sensitivity of 39.42 μA0.5/（mg（KOH）.g-l） and the detection limit of 0.0014 mg（KOH）.g^-1 （signal-to-noise ratio is 3, standard deviation is 2.247%）. Moreover, the proposed method has been successfully applied to AV determination of several transformer oil samples with advantages of rapidness, high sensitivity and accuracy compared to the conventional method.展开更多
文摘A novel modified electrode was prepared by electrochemicaly cycling scanning the glass carbon electrode covered with a macroporous alumina membrane in a solution containing PPy and PMo 12O 3- 40. The reversibility of the cyclic voltammograms was improved obviously. The remarkable advantage of the modified electrode was the high sensitivity and favorable electrocatalytic behavior toward NO - 2. The peak current increased linearly with the concentration of NO - 2 in the range of 8.0×10 -7—0.01 mol/L. The detection limit of NO - 2 was 1.0×10 -9 mol/L. The polyoxometalates nanopaticles modified electrode exhibited almost the same electrochemical behavior after 7 d. It is indicated that the PMo 12-PPy/AGCE has a good reproducibility, stability and wide linearity range.
基金Project(11JJ3015)supported by the Natural Science Foundation of Hunan Province,China
文摘A polypyrrole-modified glassy carbon electrode （PPy/GC electrode） was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry （LSV）. A well-defined new reduction peak appeared at a more positive potential than the original reduction peak. The new reduction peak current was linearly related to the acid value （AV） of oil. Based on it, a rapid electrochemical method for determining AV of transformer oil was developed using PPy/GC electrode. A working curve was obtained in the AV range of 0.01 to 0.40 mg（KOH）.g^-1, with a sensitivity of 39.42 μA0.5/（mg（KOH）.g-l） and the detection limit of 0.0014 mg（KOH）.g^-1 （signal-to-noise ratio is 3, standard deviation is 2.247%）. Moreover, the proposed method has been successfully applied to AV determination of several transformer oil samples with advantages of rapidness, high sensitivity and accuracy compared to the conventional method.
