Graphene Oxide–Al/Mn Nanocompoisites Electrochemical Sensors for Detection and Evaluation of Cadmium Ions in Aqueous Solutions

Abstract

The rising incidence of cadmium in water contamination sources presents a significant threat to environmental and community health, requiring the advancement of precise and selective detection technology. This work examines the electrochemical sensing capabilities of graphene oxide–aluminum/manganese (GO–Al/Mn) nanocomposites for detecting and evaluating of cadmium(II) ions in solutions. An innovative electrochemical sensor utilizing GO–Al/Mn nanocomposites (NCs) was synthesized to detect Cd(II) in solutions with high sensitivity and selectivity, employing a manually controlled dynamic electrochemical approach via a three-electrode system. Characterization of structural, morphological, and compositional aspects was conducted using FTIR, XRD, SEM, EDX, BET, TEM, and XPS, validating the effective incorporation of Al/Mn oxides with GO sheets. Thermal gravimetric analysis (TGA) indicated a total weight loss of over 90% for pristine graphene oxide (GO), in contrast to roughly 24.63% for GO Al/Mn nanocomposites over the temperature range of 30–800°C, underscoring the enhanced thermal stability conferred by metal oxide functionalization. The electrochemical assessment revealed a detection limit (LOD) of 1.65 µM and a quantification limit (LOQ) of 5.00 µM, exhibiting a linear response range of 100–700 µM Cd(II) and a high correlation coefficient (R² = 0.9989). The improved performance is due to the synergistic impacts of GO’s oxygenated functional groups, Al centers that attract Cd²⁺, and Mn redox sites that promote electron transport. Sensors demonstrated high selectivity for various interfering substances in the matrix of aqueous solutions and actual water samples. These findings underscore the promise of GO–Al/Mn NCs as effective, economical, and eco-friendly platforms for the environmental monitoring of Cd(II) pollutants.