An all-solid-state Ion-Selective Electrode with Ag3AsO4 as the Sensitive Membrane for Detecting Arsenate in Aqueous Environments

摘要

In this work, an all-solid-state ion-selective electrode, using Ag wire as a substrate, Ag particles as amid-layer and Ag 3 AsO 4 as a sensitive membrane was prepared for detecting arsenate in aqueousenvironments. The Ag particles were electrodeposited using a function generator and Schottky diode inAgNO 3 solution. Electrochemical polymerisation of the Ag 3 AsO 4 sensitive membrane was achievedvia chronoamperometry on an electrochemical workstation. The membrane successfully polymerisedon the surface of the electrode, which was demonstrated from scanning electron microscopy images.The energy-dispersive X-ray spectroscopy results prove that the sensitive membrane is Ag 3 AsO 4 ,based on the main elements of the sensitive membrane being determined as, As, O and Ag. Thedetection limit of the electrode was measured as 1.8165 × 10 ?6 M with a linear range of 5 × 10 ?6 –1 ×10 ?1 M, which indicates that the Ag 3 AsO 4 electrode has a wide response range and low detection limit,exhibiting a response time of around 1–2 s with good stability and repeatability. The average potentialfluctuation of the electrode in 1 h was 1.48 mV. The electrode shows good anti-interference propertiesin that it is far more sensitive to arsenate than interfering ions, including sulfate, carbonate, acetate andnitrate. The lifespan of the Ag 3 AsO 4 electrode was confirmed as being more than 80 days, showinggreat recovery in water sample testing, which shows that the electrode is accurate and can be used foraqueous environmental testing.