Tungsten oxide-iodide/poly-2-aminobenzenethiol nanocomposite with iodine intercalation as a promising electrode for potentiometric sensing of Pb2+ ions in water

Abstract

Tungsten oxide-iodide/poly-2-aminobenzenethiol nanocomposite (WO₂I₂/P2ABT) is created through the introduction of iodine into polymer chains, where iodine serves as an oxidizing agent during the synthesis process. With a highly porous structure, the sensing capabilities of WO₂I₂/P2ABT for detecting Pb²⁺ ions are successfully demonstrated, revealing a Nernstian slope of 26.2 mV/decade. This detection is accomplished through a simple potentiometric technique, employing a simple two-electrode cell setup. To further validate its performance, cyclic voltammetry is conducted using a three-electrode system, revealing a remarkable sensitivity of 7.2 × 10⁻⁵ A M⁻¹ for Pb²⁺ ions. The nanocomposite sensor's selectivity is rigorously examined by subjecting it to testing in the presence of 0.01 M interfering ions. The results unequivocally demonstrate that the sensor remains unresponsive to these interfering ions, underscoring its remarkable selectivity for Pb²⁺ ions. Moreover, the sensor's behavior is evaluated under real-world conditions using natural samples, where, no indications of interference from other ions are observed. This is estimated by the absence of cyclic peaks in the voltammogram, indicating the sensor's unique ability to selectively detect Pb²⁺ ions without being perturbed by other ions that may be naturally occurring in the samples. These findings emphasize the nanocomposite sensor's potential for a wide array of applications in environmental monitoring and analytical chemistry. Its extraordinary combination of high sensitivity, impeccable selectivity, and robust performance in practical scenarios establishes it as an invaluable tool for detecting Pb²⁺ ions across various contexts.