Pd/石墨烯/玻碳电极检测4-氯酚污染物的研究

采用改进的Hummers法和硼氢化钠还原法制备Pd/石墨烯催化剂，并采用XRD、SEM、XPS、TEM等技术对其进行表征. 将该催化剂修饰于玻碳电极表面，制备出Pd/石墨烯/玻碳电极，使用循环伏安法研究了检测4-氯酚的最佳工作条件. 研究结果表明，所得石墨烯表面平整光滑，以零价态存在的Pd纳米颗粒均匀分散到石墨烯上，平均粒径为(6.5 ± 0.05) nm. 检测4-氯酚的最佳支持电解质为0.1 mol?L-1、pH = 6.8的磷酸-磷酸钠缓冲溶液（PBS），峰电流与扫描速率的平方根呈良好的线性关系（R2 = 0.992），该电极的线性范围为1 ~ 100 μmol?L-1 (R2 = 0.967)，检测限为0.57 μmol?L-1 (S/N = 3)，且具有良好的重现性和稳定性. 本文所研制的Pd/石墨烯/玻碳电极具有较高的催化活性，提供了一种简便快捷、重现性好的检测4-氯酚的方法.

Application of Pd/Graphene Modified Electrode in the Detection of 4-Chlorophenol

The Pd/graphene composites were synthesized by a modified Hummers method and NaBH4 reduction process, and then were characterized using XRD, SEM, XPS, and TEM. The Pd/graphene modified glassy carbon electrode (Pd/graphene/GCE) was prepared based on this method. Cyclic voltammetry was used to study the optimum operation conditions for the 4-chlorophenol detection. It was shown that the surface of the graphene was smooth and Pd nanoparticles were uniformly dispersed on graphene. The average particle size was calculated to be 6.5 ± 0.05 nm. These nanoparticles exhibited high catalytic activity and sensitivity toward chlorophenols. PBS with a concentration of 0.1 mol?L-1 at pH 6.8 was the best supporting electrolyte for the detection of 4-chlorophenol. Peak current and the square root of the scan rate were in a good linear relationship (R2 = 0.992). Using the Pd/graphene/GCE analytical performance with the linear range from 1 to 100 μmol?L-1 (R2 = 0.967), a detection limit of 0.57 μmol?L-1 was obtained. The Pd/graphene/GCE had a good reproducibility and stability. Therefore, the Pd/graphene/GCE showed a high catalytic activity, which provides a simple, quick and reproducible method for the detection of 4-chlorophenol.