Leaf-Like ZIF-Derived Zinc-Cobalt Layered Double Hydroxide@Cerium Dioxide Nanosphere Heterostructure/Nickel Foam Composite Electrode for the Detection of Lead Ions in the Environment

Abstract

The lead (Pb) in the environment is harmful to human body, so it is of practical significance and application value to develop a method for detecting lead ions (Pb2+) in the environment. Herein, Zeolitic imidazolate framework/nickel foam (ZnCo ZIF-L/NF) was in situ grown on nickel foam (NF) substrate by hydrothermal method, and aged and hydrolyzed at room temperature to transform ZnCo ZIF-L into zinc cobalt layered double hydroxide/nickel foam (ZnCo ZLDH/NF). CeO2 nanospheres were synthesized and loaded onto ZnCo ZLDH/NF materials to prepare ZnCo ZLDH@CeO2/NF heterostructure composite electrodes. Finally, ZnCo ZLDH@CeO2/NF was used to detect divalent lead ion (Pb2+) by differential pulse anodic stripping voltammetry (DPASV). The electrochemical sensor constructed by the ZnCo ZLDH@CeO2/NF composite electrode exhibits the concentration linear range of 0.1 μM–30 μM with a limit of detection 9 nM (S/N = 3) and the sensitivity of 67 A/M. Meanwhile, the ZnCo ZLDH@CeO2/NF composite electrode has good repeatability and anti-interference stability.