柚皮热解炭应用于对\邻苯二酚电化学传感器

Application of pyrolysis carbon from pomelo peel in electrochemical sensors of hydroquinone and catechol

摘要:

本文以柚子皮为原料，分别以氨水、氢氧化钠和氢氧化钾为活化剂对其进行活化，然后通过一步热解法制备了一类生物炭材料。使用SEM、XRD、全自动比表面分析仪表征了几种材料的结构和形貌。并通过电化学交流阻抗技术（EIS）和循环伏安法（CV）测试了几种材料的电化学性能。相比于其它材料，经氢氧化钾活化处理后制得的热解炭孔道分布最为丰富，同时表现出最大的电导率与电活性表面积。通过滴涂法将该类炭材料分别修饰在玻碳电极表面，在PBS溶液（pH=7.0）中用微分脉冲伏安法（DPV）考察了对苯二酚（HQ）和邻苯二酚（CA）在不同电极上的电化学行为。结果表明，经氢氧化钾活化后制得的炭材料修饰电极对HQ和CA的同时检测效果最佳。在最优化条件下和0.5~100 μmol/L浓度范围内时，HQ和CA对该传感器的响应电流值随浓度线性增大，检测下限分别为0.023 μmol/L和0.040 μmol/L。同时，该传感器具有良好的稳定性，其相对标准偏差值（RSD）分别为2.3%和3.5%。通过加标回收法对实际样品中的HQ和CA进行检测，加标回收范围为97.8% ~ 101.7%。

Abstract:

In this work, pomelo peel was used as crude material, ammonia, sodium hydroxide and potassium hydroxide was used as activators, then a class of biochar materials were prepared by one-step pyrolysis. The structure and morphology of these materials were characterized by SEM, XRD, and Fully automated surface analyzer; then, the Electrochemical ac impedance technique (EIS) and Cyclic voltammetry (CV) were used to test their electrochemical properties. Compared to other materials, Pyrolytic carbon produced by activation of potassium hydroxide possessed the most abundant pore distribution, while showed the most superior electrochemical properties. This kind of carbon material was modified on the surface of glassy carbon electrode(GCE) by cast. The electrochemical behavior of hydroquinone (HQ) and catechol (CA) at different electrodes were investigated by differential pulse voltammetry (DPV) in PBS solution (pH=7.0). The results indicated that compared to other electrodes, the PC-4/GCE was the most superior to HQ and CA at the same time. Under optimal conditions, when the concentration of HQ and CA were in the range of 0.5~100 μmol/L, a good linear relationship between the PC-4/GCE response current and its concentration has been showed, the detection limits were 0.023μmol/L and 0.040μmol/L, respectively. Meanwhile, the sensor had good stability, and its relative standard deviation values (RSD) were 2.3% and 3.5%, respectively. HQ and CA in tap water samples were detected by standard recovery, and add standard recovery range was 97.8~101.7.