Stripping voltammetric determination of cadmium and lead ions based on a bismuth oxide surface-decorated nanoporous bismuth electrode
Yue Wang, Xuan Wu, Jianfeng Sun, Caiyun Wang, Guo‐Yuan Zhu, Li‐Ping Bai, Zhi‐Hong Jiang, Wei Zhang
Abstract
Ultrasensitive detection of heavy metal ions through electrochemical methods is a longstanding research topic. One of the most compelling subjects is preparation of modified electrodes with a high specific surface area as well as fast response characteristics. In this study, novel bismuth oxide surface-decorated nanoporous bismuth (Bi2O3@NPBi) was prepared through a typical dealloying method, where a bicontinuous ligament–channel structure greatly improved the electrically active surface area and electron conduction. The Bi2O3@NPBi-modified electrode was employed to detect heavy metal ions using square wave anodic stripping voltammetry (SWASV), and the corresponding limits of detection (LOD) were 0.02 and 0.03 µg/L for simultaneous detection of Pb2+ and Cd2+. Due to the high cycling stability and capacity of bismuth oxides, the relative standard deviation (RSD) of the response currents using Bi2O3@NPBi was less than 4.16%, which is very considerably lower than the RSD of NPBi. Furthermore, a Bi2O3@NPBi-modified electrode was used to determine the concentration of Pb2+ and Cd2+ in tap water samples, and excellent recovery figures were obtained as there is little interference from other co-existing ions. In conclusion, the Bi2O3@NPBi-modified electrode showed good reusability and feasibility for quality assurance in agricultural, food and environmental applications.