Ultrasound-Assisted Synthesis of Hybrid Phosphomolybdate–Polybenzidine Containing Silver Nanoparticles for Electrocatalytic Detection of Chlorate, Bromate and Iodate Ions in Aqueous Solutions

Abstract

Herein, we report a hybrid electroactive material composed of silver nanoparticle-embedded polybenzidine matrix containing phosphomolybdic acid as the active inorganic component by an ultrasound-assisted method for the electrochemical detection of chlorate, bromate and iodate ions in aqueous solutions. The prepared hybrid material was characterised for its physicochemical properties: X-ray diffraction and transmission electron microscopy analyses provided evidence for the presence of silver nanoparticles (∼12 nm) in the hybrid material. The synthesized hybrid material was successfully fabricated on a glassy carbon electrode, and cyclic voltammetry was used to probe its electrochemical properties in 1 M H 2 SO 4 solution. Amperometry was employed in order to find out the detection limits of chlorate, bromate and iodate ions in aqueous solutions. This hybrid electrochemical interface showed the lowest detection limits of 86.3 nM, 1.45 μM and 1.66 μM for bromate, iodate and chlorate, respectively. Phosphomolybdate anion (PMo12) present in the hybrid material acted as both effective mediator and the source of mobile protons at the electrochemical interface. Silver nanoparticles present in the hybrid material further influenced the electroactivity of the modified electrode.

Electrochemical Characterisation of NiII‐Crown‐Type Polyoxometalate‐Doped Polypyrrole Films for the Catalytic Reduction of Bromate in Water

“…This cyclic voltammogram exhibits three well‐defined redox couples labelled as I/I′, II/II′ and III/III′ with E 1/2 –222 mV, –320 mV and –570 mV respectively. Like the solution electrochemical behaviour of Ni‐Crown POM Figure a the redox couple I/I′ splits into the two redox couple I/I′ and II/II′ with four electron each while the redox couple III/III′ is eight electron in nature at pH‐2 buffer and is associated with the redox switching of the tungsten‐oxo centres within the polymer bound POM (as described by Equation (1)–Equation (3)) …”

Polyoxometalate-functionalized nanocarbon materials for energy conversion, energy storage and sensor systems

“…The ability of POMs to undergo reversible multi-electron redoxprocesses makes them interesting for amperometric sensor applications, such as detection of redox-active industrial and agricultural pollutants, e.g. nitrate, 81 bromate, 82 chlorate, 83 iodate, 84 and hydrogen peroxide. [85][86][87] To read out the sensing information and to maximize amperometric response, the POMs need to be anchored or immobilized on conductive substrates while at the same time maintaining molecular dispersion to reach low analyte detection limits.…”

Electrochemical investigation and amperometry determination iodate based on ionic liquid/polyoxotungstate/P-doped electrochemically reduced graphene oxide multi-component nanocomposite modified glassy carbon electrode

“…However, at higher concentrations of 1600 mmol L À1 , the noise of the amperometric signal increases, and the current stabilization take longer and longer until no straight line is achieved anymore. The linear calibration range, LOD, and sensitivity of the suggested sensor for IO 3 À determination are compared with those in previous literatures [80][81][82][83][84][85][86][87][88][89][90][91] ( Table 2). The results proved that (bdpy)SiW 11 Ni/P-ERGO/GCE is an excellent platform for IO 3 À detection.…”