高含量氮掺杂碳纳米管的合成及NO电氧化

Synthesis and NO electrooxidation of CN_x-NTs with high nitrogen content

为研制NO检测灵敏度高的电极修饰材料,以吡啶和尿素为碳源和氮源,以Fe-MgO为催化剂,在NH3下于800～900℃采用CVD法原位合成了氮掺杂碳纳米管(CNx-NTs),确定了氮的原子分数为7.05CNx-NTs的最佳合成条件.通过对透射电镜(TEM)、x-射线光电子能谱(XPS)、x-射线衍射分析仪(XRD)和Raman光谱进行研究,结果表明所合成的CNx-NTs随着反应温度的降低有序度减小,管壁缺陷增加.循环伏安法研究的NO在碳纳米管修饰电极上的电氧化行为结果表明:NO在CNx-NTs修饰电极上的电氧化活性均高于未掺杂氮的多壁碳纳米管(MWCNTs),其中,氮原子分数为7.05的CNx-NTs修饰电极的电氧化峰电位最小,峰电流密度最大,反应活性较大.该电极上NO检测的灵敏度最高,是一种比较理想的电极修饰材料.

In order to develop the electrode modified materials with high NO （nitric oxide） detection sensitivity,nitrogen-doped multi-walled carbon nanotubes （CNx-NTs） were in-situ synthesized by chemical vapor deposition （CVD） method with using Fe-MgO as catalyst as well as pyridine and urea as carbon and nitrogen sources in the temperature range of 800 to 900℃ under ammonia atmosphere. The optimal synthesis conditions for high nitrogen atom fraction content 7.05 of CNx-NTs were determined. TEM,X-ray photoelectron spectroscopy （XPS）,XRD and Raman analysis results show that with decreasing the reaction temperature,the order degree of CNx-NTs decreases and defects increases. In addition,the electrooxidation behavior of NO on CNx-NTs modified electrode was investigated with the cyclic voltammetry method. The results demonstrate that the CNx-NTs modified electrode exhibits higher electrooxidation activity than MWCNTs modified electrode,and the CNx-NTs modified electrode with nitrogen atom fraction content of 7.05 has the lowest electrooxidation peak potential,the highest peak current density and the excellent reaction activity. Due to its high NO detection sensitivity,the synthesized CNx-NTs is an excellent electrode modified material.