A Flexible Self-Supported Silver Wire with Nanoporous Skeleton for Electrochemical Sensing of Trichloroacetic Acid

Abstract

The content of chloroacetic acid in water is mandatory, so rapid and accurate detection is of great significance for environmental health. Silver has a strong specific interaction with chloridion and its three-dimensional interconnected ligaments are proved to have higher activity. Herein, a self-supported nanoporous skeleton was constructed on the surface of silver wire by directly electrochemical alloying in ZnCl2–glycol solution at 140 °C and subsequently dealloying in sulfuric acid solution. AgZn and AgZn3 alloys are formed by electrodeposition process, and the nanoporous skeleton of elemental silver is formed after dealloying. The interconnected ligaments are uniform and the pore size is about 10–200 nm. The cyclic voltammetry showed that the self-supported nanoporous skeleton of the silver wire electrode exhibited high electrocatalytic activity for trichloroacetic acid. Detected by chronoamperometry, the results show that the detection limit is 70 nM (S/N = 3) in the concentration range of 0.14–549 μM, and the sensor has high sensitivity, good reproducibility and anti-interference. And by detecting the recovery rate of trichloroacetic acid in the tap water, river water and industrial wastewater, the sensor proves the practicality of the prepared electrode.