Reduction of Nitrophenyl Films in Aqueous Solutions: How Many Electrons?

Brooksby, Paula A.; Shields, James D.; Farquhar, Anna K.; Downard, Alison J.

doi:10.1002/celc.201600395

Cited by 11 publications

(24 citation statements)

References 34 publications

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“…sp 3 carbon) can be estimated from the voltammetric response to be 0.47 nm cm −2 , assuming a two electron re-oxidation of the aryl group occurs. 35 Signficantly, no wetting response was observed within the potential window used for the other carbon substrates (see Supporting information), however regeneration of the "fresh" HOPG surface by peeling of the uppermost layers, recovered the electrowetting response.…”

Section: Resultsmentioning

confidence: 99%

Electrowetting on conductors: anatomy of the phenomenon

et al. 2017

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We have recently reported that reversible electrowetting can be observed on the basal plane of graphite, without the presence of a dielectric layer, in both liquid/air and liquid/liquid configurations. The influence of carbon structure on the wetting phenomenon is investigated in more detail here. Specifically, it is shown that the adsorption of adventitious impurities on the graphite surface markedly suppresses the electrowetting response. Similarly, the use of pyrolysed carbon films, although exhibiting a roughness below the threshold previously identified as the barrier to wetting on basal plane graphite, does not give a noticeable electrowetting response, which leads us to conclude that specific interactions at the water–graphite interface as well as graphite crystallinity are responsible for the reversible response seen in the latter case. Preliminary experiments on mechanically exfoliated and chemical vapour deposition grown graphene are also reported.

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Section: Resultsmentioning

confidence: 99%

Electrowetting on conductors: anatomy of the phenomenon

et al. 2017

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“…Nevertheless, when the second cycle of the voltammogram is finished, a very weak passivation of the surfaces is observed, which is consistent with a monolayer thin film covering the electrode surface. On the other hand, according to other workgroup studies, when applying a fixed potential, multilayers of aryl groups are formed on the electrode surface [ 27 , 28 , 29 ]. Thus, chronoamperometric experiments were carried out by applying a constant potential for 1 min, using twice the concentration of diazonium (2 mM NBTF) ( Figure 1 b).…”

Section: Resultsmentioning

confidence: 99%

Tuning the Covering on Gold Surfaces by Grafting Amino-Aryl Films Functionalized with Fe(II) Phthalocyanine: Performance on the Electrocatalysis of Oxygen Reduction

et al. 2021

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Current selective modification methods, coupled with functionalization through organic or inorganic molecules, are crucial for designing and constructing custom-made molecular materials that act as electroactive interfaces. A versatile method for derivatizing surfaces is through an aryl diazonium salt reduction reaction (DSRR). A prominent feature of this strategy is that it can be carried out on various materials. Using the DSRR, we modified gold surface electrodes with 4-aminebenzene from 4-nitrobenzenediazonium tetrafluoroborate (NBTF), regulating the deposited mass of the aryl film to achieve covering control on the electrode surface. We got different degrees of covering: monolayer, intermediate, and multilayer. Afterwards, the ArNO2 end groups were electrochemically reduced to ArNH2 and functionalized with Fe(II)-Phthalocyanine to study the catalytic performance for the oxygen reduction reaction (ORR). The thickness of the electrode covering determines its response in front of ORR. Interestingly, the experimental results showed that an intermediate covering film presents a better electrocatalytic response for ORR, driving the reaction by a four-electron pathway.

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“…Surface coverage of Ar‐NO 2 tethered surfaces was estimated from CVs recorded in KOH by summing the charges for the irreversible reduction of Ar‐NO 2 and the charge for Ar‐NHOH reoxidation and assuming a 6 electron transfer for each nitro group …”

Section: Figurementioning

confidence: 99%

Impact of the Diazonium Grafting Control on the Interfacial Reactivity: Monolayer versus Multilayer

et al. 2016

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A very simple strategy to prepare, in two steps, a versatile and sustainable monolayer platform for on‐surface chemistry is presented. The first step consists of the electroreduction of well‐known 4‐nitrobenzenediazonium in the presence of a radical scavenger, leading to a covalent monolayer surface modification. Then, a dense reactive phenylamine monolayer is obtained through the full electroreduction of the nitrophenyl moieties. The platform thus obtained is available for post‐functionalization with carboxyl derivatives through a usual peptide coupling. Attachment of a TEMPO unit, offering both redox and electrocatalytic properties, validates this approach and leads to high surface coverage and fast electron transfer. A comparison of the electrochemical properties of the modified surface with a classical multilayered post‐functionalized one highlights important differences in terms of interfacial reactivity. The results presented here justify the interest in preparing a reactive monolayer platform for molecule grafting and paves the way for simple and controlled surface chemistry without the need of synthesis.

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Reduction of Nitrophenyl Films in Aqueous Solutions: How Many Electrons?

Cited by 11 publications

References 34 publications

Electrowetting on conductors: anatomy of the phenomenon

Electrowetting on conductors: anatomy of the phenomenon

Tuning the Covering on Gold Surfaces by Grafting Amino-Aryl Films Functionalized with Fe(II) Phthalocyanine: Performance on the Electrocatalysis of Oxygen Reduction

Impact of the Diazonium Grafting Control on the Interfacial Reactivity: Monolayer versus Multilayer

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