Mendecki L., Mirica K.A. · ACS Applied Materials and Interfaces · 2018 · 19248-19257
Open a family to keep every result attached to its sample, method and conditions.
Paraphrased for this database from the authors’ stated interpretations — never quoted verbatim — and kept separate from reported measurements.
The paper reports the first experimental demonstration of efficient ion-to-electron transduction enabled by conductive MOFs in potentiometric sensors.
Caveat: Proof-of-concept devices; capacitance is still lower than some high-performing carbon transducers cited by the authors.
8 · Conclusions · Linked to 5 structured results
The authors state that sensor stability is currently limited by the intrinsic porosity and conductivity of the MOFs examined.
Caveat: No new gas-sorption or direct electrical-conductivity measurement is reported in this paper.
8 · Conclusions · Linked to 3 structured results
Adding the Ni3HHTP2 MOF layer between GCE and K+-ISM-II removes the low-frequency charge-transfer feature seen in the control, indicating faster ion-to-electron transduction.
Caveat: The result is device-level evidence rather than a direct standalone conductivity measurement.
5 · Quantifying the Efficiency · Figure 3 · Linked to 2 structured results
PXRD after potentiometric measurements indicates that Cu3HHTP2, Ni3HHTP2, and Co3HHTP2 retain crystallinity during and after analytical measurements.
Caveat: PXRD is qualitative pattern matching to bulk powders and previous reports.
18 · PXRD After Potentiometric Measurements · Figure S17 · Linked to 1 structured result
The authors attribute the large bulk capacitance to interconnected nanopores permeable to electrolyte and conductive pathways through the MOF film.
Caveat: Porosity/surface area was discussed from literature context rather than newly measured by gas sorption in this paper.
4 · Measuring the Charge-Transfer Resistance · Linked to 2 structured results
The hydrophobic Ni3HHTP2-coated surface and water-layer tests support suppressed water-layer formation at the MOF/ISM interface.
Caveat: Contact angle is lower than cited CIM carbon and PEDOT-C14 examples; water-layer drift is qualitative in the provided text.
7 · Aqueous Layer Test · Figure 6 · Linked to 3 structured results
Ni3HHTP2 was selected for detailed sensor development because it showed the highest bulk capacitance among the three MOF analogues.
Caveat: Capacitance values depend on drop-cast film thickness and film homogeneity.
5 · Quantifying the Efficiency · Linked to 3 structured results
Increasing Ni3HHTP2 film thickness decreased the high-frequency Ohmic impedance, attributed to more conductive pathways in the layered device.
Caveat: Drop-cast film inhomogeneity is explicitly noted by the authors.
4 · Measuring the Charge-Transfer Resistance · Figure 2B · Linked to 3 structured results
The authors propose double-layer charging as the main transduction pathway for Ni3HHTP2 and Co3HHTP2, with reversible redox/pseudocapacitance more important for Cu3HHTP2.
Caveat: Mechanistic assignment is interpretive; SI language includes typographical errors and does not quantify pseudocapacitance fractions.
12 · Cyclic Voltammetry · Figure S8 · Linked to 4 structured results
Names and aliases are kept exactly within the paper’s own identity model.
| Material | Composition | Structure context | Source |
|---|---|---|---|
| Co3HHTP2 MOFBrowse family: Co₃(HHTP)₂ / Co–HHTP | Co3HHTP2Co · HHTP | 2D · PristineLayered conductive metal-catecholate MOF; PXRD consistent with slipped parallel packing; XPS shows mixed Co2+/Co3+ valency. | 3 · Characterization of M3HHTP2 MOFs · Figures S1-S5 |
| Cu3HHTP2 MOFBrowse family: Cu₃(HHTP)₂ / Cu–HHTP | Cu3HHTP2Cu · HHTP | 2D · PristineLayered conductive metal-catecholate MOF; PXRD consistent with slipped parallel packing; XPS shows mixed Cu+/Cu2+ valency. | 3 · Characterization of M3HHTP2 MOFs · Figures S3-S5 |
| M3HHTP2 conductive MOF series | M3HHTP2, M = Ni, Cu, CoNi, Cu, Co · 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) | 2D · PristineTwo-dimensional triphenylene-based metal-catecholate MOFs arranged in a Kagome lattice; stacked layered structure consistent with previous reports. | 2 · Introduction · Figure 1 |
| Ni3HHTP2 MOFBrowse family: Ni₃(HHTP)₂ / Ni–HHTP | Ni3HHTP2Ni · HHTP | 2D · PristineLayered conductive metal-catecholate MOF; PXRD consistent with slipped parallel packing; XPS shows Ni2+ only. | 3 · Characterization of M3HHTP2 MOFs · Figures S2-S5 |
Sample form, processing state and composition status define the context for measurements.
| Sample | Form and role | Processing and geometry | Source |
|---|---|---|---|
| GCE/Co3HHTP2 MOF film, ca. 60 umresearch_0842__mat__mat_co3hhtp2 | Electrode · Composite Component · Composite | Co3HHTP2 dispersion drop-cast on glassy carbon and dried before electrochemical tests.glassy carbon electrode · 60 +/- 5 um | 4 · Measuring the Charge-Transfer Resistance · Figure 2 |
| GCE/Co3HHTP2 MOF/K+-ISM-II potentiometric deviceresearch_0842__mat__mat_co3hhtp2 | Electrode · Composite Sample · Composite | Co3HHTP2 MOF film covered with K+-ISM-II membrane.glassy carbon electrode | 14 · Potentiometric Responses · Figure S10 |
| Co3HHTP2 black powderresearch_0842__mat__mat_co3hhtp2 | Powder · Pristine Control · Pristine Framework | Black precipitate washed with water and acetone, then dried overnight under vacuum at 85 C. | 3 · Synthesis and Characterization of Conductive MOFs |
| GCE/Cu3HHTP2 MOF film, ca. 60 umresearch_0842__mat__mat_cu3hhtp2 | Electrode · Composite Component · Composite | Cu3HHTP2 dispersion drop-cast on glassy carbon and dried before electrochemical tests.glassy carbon electrode · 60 +/- 5 um | 4 · Measuring the Charge-Transfer Resistance · Figure 2 |
| GCE/Cu3HHTP2 MOF/K+-ISM-II potentiometric deviceresearch_0842__mat__mat_cu3hhtp2 | Electrode · Composite Sample · Composite | Cu3HHTP2 MOF film covered with K+-ISM-II membrane.glassy carbon electrode | 14 · Potentiometric Responses · Figure S10 |
| Cu3HHTP2 black powderresearch_0842__mat__mat_cu3hhtp2 | Powder · Pristine Control · Pristine Framework | Black precipitate washed with water and acetone, then dried overnight under vacuum at 85 C. | 3 · Synthesis and Characterization of Conductive MOFs |
| GCE/K+-ISM-II control without MOFresearch_0842__mat__mat_ni3hhtp2 | Electrode · Pristine Control · Composite | Potassium-selective membrane directly drop-cast on GCE without MOF conductive layer.glassy carbon electrode | 5 · Quantifying the Efficiency · Figure 3A |
| GCE/M3HHTP2 MOF film seriesresearch_0842__mat__mat_m3hhtp2_series | Electrode · Composite Component · Composite | Ni3HHTP2, Cu3HHTP2, or Co3HHTP2 dispersion drop-cast onto GCE for electrochemical characterisation.glassy carbon electrode · nominally 60 +/- 5 um for main analogue capacitance comparison | 3 · Preparation of MOF-Coated Electrodes |
| GCE/M3HHTP2 MOF/K+-ISM-II device seriesresearch_0842__mat__mat_m3hhtp2_series | Electrode · Composite Sample · Composite | Ni3HHTP2, Co3HHTP2, or Cu3HHTP2 conductive layer covered with K+-ISM-II membrane.glassy carbon electrode | 14 · Potentiometric Responses · Figure S10 |
| M3HHTP2 bulk powder seriesresearch_0842__mat__mat_m3hhtp2_series | Powder · Pristine Control · Pristine Framework | Washed and vacuum-dried bulk powders used for SEM/EDX, PXRD, and XPS comparison. | 4 · Powder X-ray Diffraction · Figure S2 |
| GCE/Ni3HHTP2 MOF film, ca. 60 umresearch_0842__mat__mat_ni3hhtp2 | Electrode · Composite Component · Composite | Ni3HHTP2 dispersion drop-cast on glassy carbon and dried before electrochemical tests.glassy carbon electrode · 60 +/- 5 um | 4 · Measuring the Charge-Transfer Resistance · Figure 2 |
| GCE/Ni3HHTP2 MOF/K+-ISM-I potentiometric deviceresearch_0842__mat__mat_ni3hhtp2 | Electrode · Composite Sample · Composite | Ni3HHTP2 MOF film covered with valinomycin-based K+-ISM-I membrane.glassy carbon electrode | 7 · Potentiometric Ion Sensing · Figure 5B |
| GCE/Ni3HHTP2 MOF/K+-ISM-II potentiometric deviceresearch_0842__mat__mat_ni3hhtp2 | Electrode · Composite Sample · Composite | Ni3HHTP2 MOF film sandwiched between GCE and K+-selective polymeric membrane.glassy carbon electrode · MOF 60 +/- 5 um for main EIS/capacitance; membrane thickness 110 +/- 10 um for water/contact-angle test | 5 · Quantifying the Efficiency · Figure 3B |
| GCE/Ni3HHTP2 MOF/NO3--ISM potentiometric deviceresearch_0842__mat__mat_ni3hhtp2 | Electrode · Composite Sample · Composite | Ni3HHTP2 MOF film covered with nitrate-selective polymeric membrane.glassy carbon electrode | 6 · Potentiometric Ion Sensing · Figure 5A |
| GCE/Ni3HHTP2 MOF thickness seriesresearch_0842__mat__mat_ni3hhtp2 | Electrode · Composite Component · Composite | Drop-cast Ni3HHTP2 films prepared with different aliquot volumes.glassy carbon electrode · 20 +/- 8, 40 +/- 5, and 60 +/- 5 um | 10 · Interferometry of GCE/Ni3HHTP2 MOF Electrodes · Figure S7 |
| Ni3HHTP2 black powderresearch_0842__mat__mat_ni3hhtp2 | Powder · Pristine Control · Pristine Framework | Black precipitate washed with water and acetone, then dried overnight under vacuum at 85 C. | 2 · Synthesis and Characterization of Conductive MOFs |