Innovative electrochemical sensing of manganese ions via zirconium ZSM5 framework -embedded carbon paste electrodes: A comprehensive study of theoretical modeling and experimental demonstration

Abstract

This work describes a low-cost method of quickly and accurately measuring manganese ions (Mn²⁺) using square wave cathodic stripping voltammetry (SWCSV) at a zirconium Zeolite Socony Mobil5 framework-embedded carbon paste electrode (Zr-ZSM5/CPE). The Zr-ZSM5-modified electrode was examined by applying Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical (EC) behavior of Mn²⁺ ions at the Zr-ZSM5/CPE. The Zr-ZSM5/CPE in a 0.1 M acetate (Act) buffer solution exhibited a distinct reduction peak when the pH and other analytical parameters, such as accumulation duration, deposition time, scan rate, and pulse amplitude, were optimized. The results indicated that the linear calibration range of Mn²⁺ ions was 0.01–10 µM (R² = 0.996), with a corresponding lower limit of quantification (LOQ) of 7.68 × 10⁻⁵µM. The new assay demonstrated good accuracy and usability as an efficient and dependable EC sensor for Mn²⁺ ion matrix analysis, with good recovery rates (93–109 %) for the trace measurement of Mn²⁺ ion residues. Moreover, the Zr-ZSM5/CPE did not interfere with Mn²⁺ ions in its detection of common ions, indicating its excellent stability. Additionally, the suggested sensor showed outstanding reproducibility, selectivity, and precision for determining Mn²⁺ ions. Computational analyses were conducted to simulate various aspects, focusing on adsorption behavior, energetic profiles, and interfacial mechanisms. Theoretical findings highlighted the Zr-ZSM5 framework's crucial role in enhancing sensing capabilities by incorporating Zr into the channels of the original ZSM5 structure. This modification improved electron transfer properties, resulting in superior reactivity and EC performance, making it a more effective material than the pristine ZSM5 zeolite framework. To our knowledge, this is the first publication discussing the use of a Zr-ZSM5/CPE with good electrocatalytic activity, selectivity, and sensitivity for Mn²⁺ion measurement. According to this work, adding the Zr atom to ZSM5 results in novel functional sites that greatly enhance the adsorption and separation processes of Mn²⁺ ions.