Recent advancements in MoS2 nanofilms have shown great potential for water-related environmental applications, yet a MoS2 nanofilm-coated sensor for heavy metal detection has not been explored until now. This study introduces a novel sensor with vertically aligned 2D MoS2 (edge exposed) nanofilms for in situ lead ion (Pb2+) detection. The sensor demonstrated an excellent linear relationship for Pb2+ detection between 0 and 20 ppb at −0.45 V vs Ag/AgCl using square wave anodic stripping voltammetry (SWASV), with an improved limit of detection (LOD) of 0.3 ppb in tap water. It exhibited 2.8 times greater sensitivity compared to a previous metallic (Bi) composite electrode, with a lower relative standard deviation for repetitive measurements (n = 11), indicating enhanced reproducibility. Additionally, it showed 2.6 times higher sensitivity than horizontally aligned 2D MoS2 (basal plane exposed). Density functional theory calculations revealed higher adsorption energy of Pb on the MoS2 side edge (4.11 eV) compared to the basal plane (0.36 and 0.07 eV). The sensor’s band gap center was found to be higher than the Pb2+ reduction potential, enhancing its ability to reduce Pb2+. Overall, the vertically aligned 2D MoS2 sensor proved to be highly effective and reliable for detecting Pb2+ in real drinking water environments.-Scientific Journal cover design by scapiens.
[Scientific Journal cover design] Low-Thermal-Budget Fluorite-Structure Ferroelectrics for Future Electronic Device Applications
In article number 2100028, Jiyoung Kim, Si Joon Kim, and their team review key factors involved in developing fluorite-structure ferroelectrics
