Pd/石墨烯/玻碳电极检测4-氯酚污染物的研究

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

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、p H 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1~100μmol·L-1（R2=0.967）,检测限为0.57μmol·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.

The Pd/graphene composites were synthesized by a modified Hummers method and Na BH4 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-1at p H 6.8 was the best supporting electrolyte for the detection of4-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 0.57μmol·L-1was 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.