对甲酚在碳纳米管修饰电极上的电化学行为及其测定

研究了对甲酚在多壁碳纳米管修饰玻碳电极（MWNTs／GC）上的电化学行为。MWNTs／GC电极对对甲酚具有良好的电催化作用，相比玻碳电极对甲酚的氧化峰电位负移731TIV，峰电流约为玻碳电极上的4倍。同一电极重复扫描10次后，对甲酚在碳纳米管上的峰电流仍能达到最初电流的86．8％，而GC电极在相同浓度对甲酚中重复扫描3次后，峰电流降到最初电流的37．2％，表明碳纳米管提高了GC电极检测对甲酚的稳定性。研究了溶液pH值和扫描速率对对甲酚氧化的影响。并采用计时电流法研究了峰电流与对甲酚的浓度关系，结果显示峰电流与对甲酚的浓度在2．0×10^-7～2．0×10^-4mol／L范围内呈良好线性关系，检出限为9．3×10^-8mol／L（S／N=3）。

Electrochemical Behavior and Determination of P-cresol on Carbon Nanotubes Modified Electrode

In this paper, electrochemical behavior of p-cresol on MWNTs modified glassy carbon electrode （MWNTs/ GC） was studied. The result shows that MWNTs/GC electrode plays a great role on catalyzing the p cresol oxidation. Compared with the glassy carbon electrode, the anodic peak potential of p-cresol shifts negatively for 73 mV,and oxidation peak current reaches 4 times. After scanned one electrode repeatedly for 10 times, the oxidation peak current of p-cresol on MWNTs/GC electrode still retains 86.8% of the original current,while rescan p-cresol at GC electrode for 3 times,the oxidation peak current decreased to 37.2% of the original current, the results show that the MWNTs/GC electrode can improve the stability of GC electrode. Moreover the influences of the pH value and scan rates on the oxidation of p-cresol were also studied and the relationship between current and concentration of p-cresol was studied by chronoamperometry. Finally the results show that the peak current is linearly proportional to the concentration of p-cresol in the range from 2.0 ×10^-7 to 2.0 ×10^-4 mol/L,the detection limit is g. 3×10^-8 mol/L（S/N=3）.