Transition Metal-Substituted Krebs-Type Polyoxometalate-Doped PEDOT Films

Abstract

The transition metal-substituted Krebs-type polyoxometalates (POMs) [Sb 2 W 20 M 2 O 70 (H 2 O) 6 ] n− , M = Fe(III), Co(II), or Cu(II), were surface immobilized within the conducting polymer 3,4-ethylenedioxythiophene (PEDOT) on glassy carbon electrode surfaces. The immobilized films of different thicknesses were characterized by electrochemical and surfacebased techniques. The inherent redox activity for the Krebs-type POMs, [Sb 2 W 20 M 2 O 70 (H 2 O) 6 ] n− , M = Fe(III), Co(II), or Cu(II), that were observed in the solution phase were maintained in the polymeric PEDOT matrix. The resulting films were found to be extremely stable toward redox switching between the various POM-based redox states. The films exhibited pH-dependent redox activity and thin layer behavior up to 100 mV s −1 . The films were found to be highly conductive through the employment of electrochemical impedance spectroscopy. Surface characterization of the films was carried out by X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy graph.

Electrochemical Behaviour of (n‐Bu4N)4[AsVMo11O40] and (n‐Bu4N)4[AsV2Mo10O40] Doped PEDOT Film and Its Quartz Crystal Microbalance Studies

“…Moreover, the detection of small mass variations which can be associated with specific fluxes to discriminate different steps of the doping‐dedoping process namely the participation of small cations. Naseer and co‐workers have fabricated and reported the electrochemical properties of transition metal‐substituted Krebs‐type POMs, [Sb 2 W 20 M 2 O 70 (H 2 O) 6 ] n− , M=Fe(III), Co(II), or Cu(II), immobilized within the conducting polymer PEDOT [27] . According to Chunchen Yuan et al .…”

“…Naseer and co-workers have fabricated and reported the electrochemical properties of transition metalsubstituted Krebs-type POMs, [Sb 2 W 20 M 2 O 70 (H 2 O) 6 ] nÀ , M = Fe(III), Co(II), or Cu(II), immobilized within the conducting polymer PEDOT. [27] According to Chunchen Yuan et al a counter electrode made of SiW 11 -PEDOT hybrid film demonstrated an efficiency that was almost as high as that of DSSCs with Pt CEs. [28] Immobilization of POM redox centres in PEDOT hybrid film demonstrated improved charge propagation dynamics and potential applications in electrocatalysis.…”

Geometric Frustration and Long-Range Ordering Induced by Surface Pressure Oscillation in a Langmuir–Blodgett Monolayer of Magnetic Soft Spheres

“…Integration as thin films remains a challenge. Their high solubility in water is an obvious problem which makes it impossible to obtain POMs as monolayers on water that can be transferred to a substrate as L-B films, and a significant amount of work has been channeled toward its advancement. − However, a POM enclosed in an organic surfactant can be easily spread directly on water to form stable 2-D Langmuir monolayers . Xu et al studied Langmuir films of surfactant-encapsulated clusters (SEC) in which the cationic surfactant dimethyldioctadecylammonium (DODA) replaced the counter cations of Keggin-type polyoxometalate (POM) clusters, AW 12 O 40 z‑ (A, z = P, 3; Si, 4; B, 5; Co, 6).…”