Conductive Mesoporous Catalytic Films. Current Distortion and Performance Degradation by Dual-Phase Ohmic Drop Effects. Analysis and Remedies

Andrieux, C.P.; Costentin, Cyrille; Giovanni, Carlo Di; Savéant, Jean‐Michel; Tard, Cédric

doi:10.1021/acs.jpcc.6b07013

Cited by 23 publications

(28 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The Tafel slope significantly decreases to 58.7 mV dec −1 for five half‐layer Hi−Ni, compared to the conventional Ni electrode (92.6 mV dec −1 ), which can show different values depending on its composition . Tafel slopes can also be influenced by a low efficiency of current conduction in the solid portion of the film and in the pores . The related ohmic drop may strongly affect the characteristic catalytic features, but this doesn't seem to be the case for the present hierarchical structures.…”

Section: Resultsmentioning

confidence: 73%

See 1 more Smart Citation

Hierarchical Multiporous Nickel for Oxygen Evolution Reaction in Alkaline Media

et al. 2019

View full text Add to dashboard Cite

Electrochemical water splitting is a crucially important process for energy conversion and storage. In this context, we report the synthesis of hierarchical multiporous nickel nanosheets obtained by a templated two-step electrodeposition of nickel in the presence of silica beads and an assembly of nonionic surfactant in order to generate a combined macro-and mesoporous structure. Interestingly, the synergistic effect of these highly ordered meso-and macroporous structures promotes the catalytic performance for oxygen evolution reaction with one order of magnitude higher current densities and a better stability of the electrodes compared to flat nickel or electrodes having a single type of porosity. This example illustrates a promising strategy for the rational design of highperformance porous metals, not only in the frame of water electrolysis, but also for other electrocatalytic applications.[a] S. Assavapanumat, M. Ketkaew, P. Garrigue, V. Lapeyre, Dr.

show abstract

Section: Resultsmentioning

confidence: 73%

“…Silica particles of 920 nm diameter were synthesized following modified literature procedures, and then used as colloidal crystal templates transferred onto a gold‐coated glass slide by using the Langmuir‐Blodgett (LB) technique . Prior to silica template deposition, the gold substrate was cleaned with isopropanol and plasma, respectively.…”

Section: Methodsmentioning

confidence: 99%

Hierarchical Multiporous Nickel for Oxygen Evolution Reaction in Alkaline Media

et al. 2019

View full text Add to dashboard Cite

show abstract

“…8). The large peak-to-peak separations (0.43 and 0.46 V) are commonly observed in MOF electrochemistry and are attributed to sluggish interfacial electron transfer, ohmic resistance in the film, and/or slow ion transport at the film|electrolyte interface [33][34][35][36][37] .…”

Section: Resultsmentioning

confidence: 99%

Enhancing photovoltages at p-type semiconductors through a redox-active metal-organic framework surface coating

et al. 2020

View full text Add to dashboard Cite

Surface modification of semiconductors can improve photoelectrochemical performance by promoting efficient interfacial charge transfer. We show that metal-organic frameworks (MOFs) are viable surface coatings for enhancing cathodic photovoltages. Under 1-sun illumination, no photovoltage is observed for p-type Si(111) functionalized with a naphthalene diimide derivative until the monolayer is expanded in three dimensions in a MOF. The surface-grown MOF thin film at Si promotes reduction of the molecular linkers at formal potentials >300 mV positive of their thermodynamic potentials. The photocurrent is governed by charge diffusion through the film, and the MOF film is sufficiently conductive to power reductive transformations. When grown on GaP(100), the reductions of the MOF linkers are shifted anodically by >700 mV compared to those of the same MOF on conductive substrates. This photovoltage, among the highest reported for GaP in photoelectrochemical applications, illustrates the power of MOF films to enhance photocathodic operation.

show abstract

“…However, under the same conditions, the photocathode functionalized with a monolayer of the NDI linker, NDITiO2@Si, exhibits two redox events in the CV (Figure 2a and Table 1 resistance in the film, and/or slow ion transport at the filmelectrolyte interface. [34][35][36][37][38] Photovoltage of Zr(NDI)lTiO2@Si…”

Section: Cyclic Voltammetry At Illuminated Silicon Photocathodesmentioning

confidence: 99%

Enhancing Photovoltages at p-Type Semiconductors Through a Redox-active Metal-Organic Framework Surface Coating

Beiler¹,

McCarthy²,

Johnson³

et al. 2020

Preprint

View full text Add to dashboard Cite

Metal-organic frameworks (MOFs) interfaced with visible-light-absorbing semiconductors offer a novel approach to improve photoelectrochemical performances. When tested under 1-sun illumination, a naphthalene diimide (NDI)-based monolayer immobilized at p-type Si(111) undergoes two sequential one-electron reductions close to their thermodynamic potentials. No photovoltage is observed until the NDI monolayer is expanded in three dimensions in a PIZOF-type Zr(NDI) MOF (PIZOF = porous interpenetrated zirconium organic framework). The surface-grown MOF thin film promotes photo-induced charge separation and electron transfer across the interface and through the film, resulting in reduction of the molecular linkers at formal potentials >300 mV positive of their thermodynamic potentials. The apparent diffusion coefficient is similar to that measured at a conductive electrode (10-10 cm2 s-1), indicating that the observed photocurrent is governed by charge diffusion through the Zr(NDI) MOF film. The charges accumulated in the NDI-based MOF can be extracted by an external electron acceptor, demonstrating sufficient conductivity throughout the MOF film to power reductive transformations. When grown on GaP(100), the potentials of the NDI reductions in the MOF film are shifted anodically by >700 mV compared to those of the same MOF on conductive substrates. This photovoltage, among the highest reported for GaP in photoelectrochemical applications, illustrates the power of MOF thin films to improve photocathodic performance.

show abstract

Conductive Mesoporous Catalytic Films. Current Distortion and Performance Degradation by Dual-Phase Ohmic Drop Effects. Analysis and Remedies

Abstract: International audienc

Cited by 23 publications

References 49 publications

Hierarchical Multiporous Nickel for Oxygen Evolution Reaction in Alkaline Media

Hierarchical Multiporous Nickel for Oxygen Evolution Reaction in Alkaline Media

Enhancing photovoltages at p-type semiconductors through a redox-active metal-organic framework surface coating

Enhancing Photovoltages at p-Type Semiconductors Through a Redox-active Metal-Organic Framework Surface Coating

Contact Info

Product

Resources

About