Simple potentiometry and cyclic voltammetry techniques for sensing Hg 2+ ions in water using a promising flower-shaped WS 2 -WO 3 /poly-2-aminobenzene-1-thiol nanocomposite thin film electrode.

A highly promising flower-shaped WS 2 -WO 3 /poly-2-aminobenzene-1-thiol (P2ABT) nanocomposite was successfully synthesized via a reaction involving 2-aminobenzene-1-thiol, Na 2 WO 4 , and K 2 S 2 O 8 as oxidants. The WS 2 -WO 3 /P2ABT nanocomposite demonstrated remarkable potential as a sensor for detecting harmful Hg 2+ ions in aqueous solutions. The sensing behavior was evaluated over a wide concentration range, from 10 -6 to 10 -1 M, using a simple potentiometric study on a two-electrode cell. The calibration curve yielded an excellent Nernstian slope of 33.0 mV decade -1 . To further validate the sensing capabilities, cyclic voltammetry was employed, and the results showed an increasing trend in the cyclic voltammetry curve as the Hg 2+ concentration increased from 10 -6 to 10 -1 M with an evaluated sensitivity of 2.4 μA M -1 . The WS 2 -WO 3 /P2ABT nanocomposite sensor exhibited exceptional selectivity for detecting Hg 2+ ions, as no significant effects were observed from other interfering ions such as Zn 2+ , Ni 2+ , Ca 2+ , Mg 2+ , Al 3+ , and K + ions in the cyclic voltammetry tests. Furthermore, the sensor was tested on a natural sample that was free of Hg 2+ ions, and the cyclic voltammetry curves did not produce any characteristic peaks, confirming the sensor's specificity for Hg 2+ detection. The sensor's cost-effectiveness and ease of fabrication present the potential for developing a simple and practical sensor for detecting highly poisonous ions in aqueous solutions.