Duan J., Chen S., Zhao C. · Nature Communications · 2017 · 15341
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 aqueous deposition strategy is presented as generic, extending to stainless steel mesh substrates and Cu-MOF nanosheets on nickel foam.
Caveat: Generality is demonstrated by morphology/AFM examples, not by transport/electrocatalysis for every additional material.
6 · Discussion · Linked to 3 structured results
The same NiFe-MOF electrode is bifunctional, showing the lowest HER overpotential and highest HER TOF among the paper’s Ni-MOF, bulk and calcined controls.
Caveat: HER values are application metrics; no standalone electronic transport during HER is measured.
3 · Electrocatalytic oxygen and hydrogen evolution · Linked to 5 structured results
NiFe-MOF/NF is the best first-hand OER sample in this paper by overpotential, Tafel slope, TOF and stability among the reported controls.
Caveat: Comparison is within the authors’ reported conditions without iR correction.
3 · Electrocatalytic oxygen and hydrogen evolution · Linked to 6 structured results
A two-electrode cell using NiFe-MOF as both anode and cathode reaches 10 mA cm-2 at 1.55 V and remains stable for 20 h, outperforming the paper’s Pt/C + IrO2 benchmark cell under the stated comparison.
Caveat: Benchmark cell voltage is calculated from the reported 70 mV difference.
3 · Electrocatalytic overall water splitting · Linked to 5 structured results
Direct growth of NiFe-MOF on nickel foam avoids insulating binder and lowers electrode internal resistance compared with Nafion-assisted bulk NiFe-MOF/NF, improving electron transport.
Caveat: Internal resistance comes from EIS in electrolyte rather than dry intrinsic conductivity.
5 · Discussion · Linked to 2 structured results
The NiFe-MOF/NF electrode combines nickel-foam macropores, tens-of-nanometre open pores between vertical nanosheets, mesopores and intrinsic microporosity, supporting electrolyte/product mass transport during water splitting.
Caveat: Mass-transport role is inferred from structural characterisation and electrocatalytic performance; no direct diffusion coefficient is reported.
5 · Discussion · Linked to 4 structured results
Ultrathin NiFe-MOF nanosheets expose molecular Ni/Fe metal sites to electrolyte, giving a larger double-layer capacitance and better catalytic performance than bulk or calcined controls.
Caveat: Cdl is an electrochemical surface-area proxy, not a direct active-site count.
5 · Discussion · Linked to 6 structured results
The nanosheet array forms by a dissolution-crystallisation mechanism, evolving from microrods at 3 h to small nanosheets at 10 h and large nanosheets at 20 h.
Caveat: Mechanism is inferred from time-dependent morphology rather than in situ tracking.
2 · Results · Supplementary Fig. 4 · Linked to 3 structured results
2D nanostructuration gives NiFe-MOF nanosheets intrinsic conductivity about three orders of magnitude higher than the bulk counterpart, attributed by the authors to vacancy engineering and increased carrier concentration in metal octahedral units.
Caveat: Mechanistic vacancy/carrier explanation is interpretive; conductivity values are directly reported but only as pressed-film/pellet measurements.
5 · Discussion · Linked to 2 structured results
Names and aliases are kept exactly within the paper’s own identity model.
| Material | Composition | Structure context | Source |
|---|---|---|---|
| Bulk NiFe-MOF powder | NiFe-MOF composition not separately refined; related to NiFe-MOFMixed Ni/Fe MOF nodes. · 2,6-naphthalenedicarboxylate. | 2D · PristineBulk counterpart made of aggregated nanosheets and lacking the hierarchical nanosheet-array morphology. | S4 · Supplementary Figure 2 · Supplementary Fig. 2 |
| Calcined NiFe-MOF derived control | Calcined NiFe-MOF-derived material; exact phase not reportedNi/Fe-derived inorganic sites after calcination. · Molecular NiFe MOF sites removed/altered by calcination. | unknown · DerivedCalcined control at 650 deg C in N2, described as without molecular NiFe sites. | 3 · Electrocatalytic oxygen and hydrogen evolution |
| Cu-MOF ultrathin nanosheet array | Not reported; Cu-based naphthalenedicarboxylate MOFCu MO6 units by analogy to the stated M = Ni, Fe or Cu framework. · 2,6-naphthalenedicarboxylate. | 2D · PristineCopper-based MOF nanosheets grown on nickel foam; SEM, EDS and AFM shown. | 6 · Discussion · Supplementary Fig. 28 |
| Fe-MOF/NF control | Not reported; iron-only naphthalenedicarboxylate MOF controlFe-containing MOF nodes, Ni omitted. · 2,6-naphthalenedicarboxylate. | 2D · PristineFe-only MOF control reported for OER comparison. | 3 · Electrocatalytic oxygen and hydrogen evolution |
| Iridium(IV) oxide benchmark catalyst | IrO2Ir oxide. · None. | unknown · UnknownCommercial benchmark OER catalyst. | S1 · Supplementary Methods; Chemicals |
| Organic-ligand-only nickel foam control | 2,6-naphthalenedicarboxylic acid dipotassium on nickel foam controlNo added metal salt; nickel foam substrate present. · 2,6-naphthalenedicarboxylic acid dipotassium. | 0D · Model SystemControl showing no ligand deposition under the synthetic condition. | S3 · Supplementary Figure 1 · Supplementary Fig. 1 |
| Ni-MOF array control | Ni(C12H6O4)(H2O)4-like nickel naphthalenedicarboxylate hydrateNi octahedral MO6 units. · 2,6-naphthalenedicarboxylate. | 2D · PristineNickel-only MOF control, described as without Fe; XRD comparison close to Ni(C12H6O4)(H2O)4. | 3 · Electrocatalytic oxygen and hydrogen evolution |
| Nickel foam substrate/control | NiMetallic nickel substrate. · None. | unknown · UnknownMacroporous nickel foam substrate, also tested as a no-MOF control. | S1 · Supplementary Methods; Chemicals |
| NiFe-MOF ultrathin 2D metal-organic framework | Main text: Ni0.8Fe0.2(C12H6O4)(H2O)4; SI EDS/ICP variants: Ni0.86Fe0.14(C12H6O4)(H2O)4 and Ni0.83Fe0.17(C12H6O4)(H2O)4Mixed Ni/Fe octahedral MO6 units; Ni2+ and Fe3+ indicated by XPS. · 2,6-naphthalenedicarboxylate / 2,6-naphthalenedicarboxylic acid dipotassium. | 2D · PristineAlternating organic hydrocarbon layers and inorganic metal-oxygen layers; each metal ion coordinated to two trans monodentate carboxylates and four water molecules. | 2 · Results; Characterizations of the NiFe-MOF electrode · Figure 1; Figure 2 |
| Pt/C cathode plus IrO2 anode benchmark cell | Pt/C + IrO2Pt and Ir oxide benchmark electrocatalysts. · None. | unknown · CompositeBenchmark full-water-splitting electrode pair. | 5 · Electrocatalytic overall water splitting · Figure 4c |
Sample form, processing state and composition status define the context for measurements.
| Sample | Form and role | Processing and geometry | Source |
|---|---|---|---|
| Bulk NiFe-MOF powder drop-cast on nickel foamresearch_0071__mat__mat_bulk_nife_mof | Electrode · Pristine Control · Composite | NiFe-MOF powder dispersed in isopropanol/water with 1 wt% Nafion and drop-cast at 0.3 mg cm-2 loading.Nickel foam | S1 · Supplementary Methods · Synthesis of bulk NiFe-MOF/NF |
| Cu-MOF/NF nanosheet sampleresearch_0071__mat__mat_cu_mof | Electrode · Target Sample · Pristine Framework | Prepared similarly to NiFe-MOF/NF except Cu(Ac)2 was used as metal precursor.Nickel foam · AFM thickness ca. 6.8 nm | S30 · Supplementary Figure 28 · Supplementary Fig. 28 |
| Fe-MOF/NF controlresearch_0071__mat__mat_fe_mof | Electrode · Pristine Control · Pristine Framework | Prepared as Fe-only MOF control; exact recipe not stated.Nickel foam | 3 · Electrocatalytic oxygen and hydrogen evolution |
| IrO2 benchmark electroderesearch_0071__mat__mat_iro2 | Electrode · Pristine Control · Unknown | Commercial IrO2 benchmark, 0.3 mg cm-2 loading in SI Table 1.Electrode substrate not fully specified for OER benchmark | S31 · Supplementary Table 1 · Supplementary Table 1 |
| Organic-ligand-only nickel foam controlresearch_0071__mat__mat_ligand_control | Electrode · Pristine Control · Model | Synthetic condition with only organic ligand and no added metal salts.Nickel foam | S3 · Supplementary Figure 1 · Supplementary Fig. 1 |
| Ni-MOF/NF array controlresearch_0071__mat__mat_ni_mof | Electrode · Pristine Control · Pristine Framework | Prepared analogously to NiFe-MOF but without Fe; exact precursor amount not stated.Nickel foam | 3 · Electrocatalytic oxygen and hydrogen evolution |
| Bare nickel foam controlresearch_0071__mat__mat_nickel_foam | Electrode · Pristine Control · Unknown | No MOF deposited; used as substrate/control.Nickel foam · 1.6 mm | 3 · Electrocatalytic oxygen and hydrogen evolution |
| Calcined NiFe-MOF controlresearch_0071__mat__mat_calcined_nife_mof | Electrode · Pristine Control · Derived Carbon | Calcined at 650 deg C for 6 h in N2 with 5 deg C min-1 ramp.Derived from NiFe-MOF electrode | S1 · Supplementary Methods · Calcination of NiFe-MOF |
| NiFe-MOF/GC macrodisc electroderesearch_0071__mat__mat_nife_mof | Electrode · Pristine Control · Composite | NiFe-MOF drop-cast on glassy carbon at 0.3 mg cm-2 loading.Glassy carbon macrodisc | S12 · Supplementary Figure 10 · Supplementary Fig. 10 |
| NiFe-MOF/NF ultrathin nanosheet array electroderesearch_0071__mat__mat_nife_mof | Electrode · Target Sample · Mixed Metal | Directly grown in situ by aqueous chemical bath deposition; rinsed after 1 min bath ultrasonication.Nickel foam (2 cm x 1 cm x 1.6 mm in synthesis; macroporous NF support) · AFM nanolayer thickness ca. 3.5 nm; nickel foam thickness 1.6 mm | 2 · Results; Characterizations of the NiFe-MOF electrode · Figure 2 |
| Pressed NiFe-MOF nanosheet thin film for four-point-probe conductivityresearch_0071__mat__mat_nife_mof | Thin Film · Target Sample · Mixed Metal | 2D MOF nanosheets scratched from nickel foam and pressed at 10 MPa for 3 min.Pressed pellet/thin film from nanosheets scratched from nickel foam · ca. 240 nm by Supplementary Fig. 25; Methods also state circular pellet 43 um thick for conductivity measurement | 5 · Discussion · Supplementary Fig. 25 |
| NiFe-MOF on stainless steel meshresearch_0071__mat__mat_nife_mof | Electrode · Target Sample · Mixed Metal | Prepared similarly to NiFe-MOF/NF except stainless steel mesh was used as support.Stainless steel mesh · few nanometres; lateral size several micrometres | S29 · Supplementary Figure 27 · Supplementary Fig. 27 |
| Pt/C cathode plus IrO2 anode benchmark full cellresearch_0071__mat__mat_ptc_iro2_benchmark | Electrode · Pristine Control · Composite | Pt/C cathode and IrO2 anode used as benchmark for full water splitting.Two-electrode benchmark cell | 5 · Figure 4 caption · Figure 4c |
| Two-electrode cell using two NiFe-MOF electrodesresearch_0071__mat__mat_nife_mof | Electrode · Target Sample · Mixed Metal | Two-electrode water-splitting configuration using NiFe-MOF as both anode and cathode.Two NiFe-MOF electrodes on nickel foam used as anode and cathode | 3 · Electrocatalytic overall water splitting · Figure 4c |