Electrocatalytic Study of the Thin Metallopolymer Film of [2,2′‐{1,2‐Ethanediylbis[Nitrilo(1E)‐1‐Ethyl‐1‐Ylidene]}Diphenolate]‐Nickel(II) for Ethanol Electrooxidation

Abstract

The present paper describes the electrochemical activity of a Ni(II)‐Schiff base metallopolymer electrode for the oxidation of ethanol in alkaline media. The scanning electron microscope results show that the metallopolymer at the glassy carbon surface has a nanoflake‐like lamellar structure, and there is no molecular structural change after treatment with NaOH. Voltammetry measurements indicate that the metallopolymer acts as efficient material for the electrocatalytic oxidation of ethanol, where a high‐valent nickel(IV) was revealed as the reactive intermediate during the anodic scan. An isopotential point can be observed in rotating disk electrode voltammetry for ethanol oxidation. The electrode surface may be considered to consist of two independent electrochemical regions, one corresponding to the ethanol electro‐oxidation by nickel(IV) and the second corresponding to water oxidation. The Tafel slopes were found to be 246 mV dec−1 at low overpotentials and 44 mV dec−1 at high overpotentials, which suggest that the first electron transfer step is the rate controlling step. The specific activity of the metallopolymer‐modified electrode for the ethanol electro‐oxidation reaction was 6.66 mA cm−2 for 0.130 μmol cm−2 of electroactive species of metallopolymer at 0.6 V vs. SCE.

Electrocatalytic Ethanol Oxidation on Cobalt–Bismuth Nanoparticle-Decorated Reduced Graphene Oxide (Co–Bi@rGO): Reaction Pathway Investigation toward Direct Ethanol Fuel Cells

“…Moreover, it is clear from the data that Co–Bi@rGO shows better electrochemical performance compared to the related systems reported in the literature. Accordingly, comparative data of current density and onset potential of different electrocatalysts toward ethanol oxidation reaction are shown in Table . ,,− …”

Ni(OH)2-Type Nanoparticles Derived from Ni Salen Polymers: Structural Design toward Functional Materials for Improved Electrocatalytic Performance

“…The C dl of both NP-based materials was replaced by the CPE′ because those materials were not behaving like an ideal capacitor. The values of R ct are characteristic of probing the rate of charge transfer. , The R ct values are higher for NPs derived from poly­(NiSaltMe)-PS high than those observed for NPs derived from poly­( meso -NiSaldMe)-PS low (Table S4). Furthermore, C dl values obtained for NPs derived from poly­( meso -NiSaldMe)-PS low are higher than those for NPs derived from poly­(NiSaltMe)-PS high (Table S4).…”

Electrocatalytic Reduction of CO2 in Water by a Palladium-Containing Metallopolymer

“…The typical electron-forming mechanism of films based on metal–salen type complexes has been extensively studied and consolidated in the literature. The electron-deficient cation radical formed during the anode scan interacts with the electron-rich π-conjugated system of an adjacent monomer, forming bridges between the molecules [ 21 , 25 , 26 , 31 ]. This mechanism is possible due to the effective interactions between the d-center orbitals of the metal center and the π orbitals of the aromatic ring of a second metal-complex molecule.…”

“…According to Elmas et al [ 16 ], metallopolymers exhibit a well-defined coordination environment, which can be applied in the development of smart materials with the redox properties of a transition metal cation. In electrocatalytic applications, metallopolymers function as hybrid materials capable of incorporating better catalytic properties than transition metals in conducting systems [ 17 , 18 , 19 , 20 , 21 ]. In our research group, we have studied the electrocatalytic properties of metallopolymers containing salen moieties complexed with different metals in the application of fuel cells [ 21 , 22 ], chemiresistor sensors [ 23 ], and electrochemical sensors [ 24 , 25 , 26 ].…”

“…In electrocatalytic applications, metallopolymers function as hybrid materials capable of incorporating better catalytic properties than transition metals in conducting systems [ 17 , 18 , 19 , 20 , 21 ]. In our research group, we have studied the electrocatalytic properties of metallopolymers containing salen moieties complexed with different metals in the application of fuel cells [ 21 , 22 ], chemiresistor sensors [ 23 ], and electrochemical sensors [ 24 , 25 , 26 ]. The materials consist of an extended three-dimensional network formed by axial coordination of the d orbitals of the central metal with the π orbital of the phenolate moiety of the adjacent complex.…”