Ni Q., Zhang S., Wang K. et al. · Journal of Materials Chemistry A · 2024 · 31253-31261
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.
NiFe-MOF-CQD functions as an efficient non-precious-metal OER anode catalyst in a PEM electrolyser, reaching 2 A cm-2 at 2.00 V and maintaining ampere-level operation for over 7 h.
Caveat: PEM cathode uses commercial Pt/C, and long-term stability is only reported for about seven hours.
31259-31260 · Results and discussion; Conclusions · Figure 5 · Linked to 3 structured results
Despite discussing enhanced electron transport, the paper does not report direct electrical conductivity, mobility, thermoelectric, Hall, Seebeck or porosity/BET measurements for the MOF materials.
Caveat: Based on full main/SI text read and supplied renders; porosity is mentioned only as a general MOF motivation.
31254 · Introduction
Ni and Fe have a synergistic bimetallic effect: Ni primarily drives water oxidation while Fe plays an auxiliary role at Fe:Ni = 1:7, making NiFe-MOF superior to Ni-MOF and Fe-MOF controls.
Caveat: The single-metal comparison is reported qualitatively in text and graphically in Figure S8, without tabulated kinetic values.
31257 · Results and discussion · Figure S8 · Linked to 1 structured result
CQD-induced electron-donating and electron-withdrawing effects promote electron transfer between metal and oxygen atoms, optimising the electronic structure and contributing to improved OER performance.
Caveat: The paper infers enhanced electron transport from XPS shifts and electrochemical trends; no direct electrical conductivity measurement is reported.
31257 · Results and discussion · Figure 3 · Linked to 4 structured results
CQD incorporation modulates NiFe-MOF structural evolution, converting bulky/stacked sheets into ultrathin nanosheets and reducing thickness from about 150 nm to about 10 nm.
Caveat: Thickness values are AFM-derived approximate values; no raw AFM profiles beyond the figures are supplied.
31255 · Results and discussion · Figure 2 · Linked to 3 structured results
In situ FTIR indicates that OER on NiFe-MOF-CQD mainly follows the adsorbate evolution mechanism rather than the lattice oxygen evolution mechanism.
Caveat: Mechanistic assignment is based on spectroscopic intermediate bands under alkaline test conditions.
31258 · Results and discussion · Figure 4g,h · Linked to 3 structured results
Names and aliases are kept exactly within the paper’s own identity model.
| Material | Composition | Structure context | Source |
|---|---|---|---|
| Carbon quantum dots (CQDs) | C/N/F/S/Na-containing carbon quantum dots from p-phenylenediamine and sodium trifluoromethanesulfonate | 0D · PristineCarbon quantum dots with about 3.07 nm lateral size, 2-6 nm height, blue fluorescence, broad XRD peak around 20 degrees and Raman D/G bands. | 31254-31255 · 2.2 Synthesis of CQDs; 3 Results and discussion · Figures S2, S4 and S6 |
| Fe-MOF | Fe organic framework based on Fe(NO3)3 and H2NDC; exact empirical formula not reportedFe centres only · 1,4-naphthalenedicarboxylic acid (H2NDC) | 2D · PristineSingle-metal Fe analogue synthesised under the same procedure as NiFe-MOF for bimetallic-control electrooxidation testing. | 31254 · 2.3 Synthesis of NiFe-MOF · Figure S8 |
| Ni-MOF | Ni organic framework based on Ni(Ac)2 and H2NDC; exact empirical formula not reportedNi centres only · 1,4-naphthalenedicarboxylic acid (H2NDC) | 2D · PristineSingle-metal Ni analogue synthesised under the same procedure as NiFe-MOF for bimetallic-control electrooxidation testing. | 31254 · 2.3 Synthesis of NiFe-MOF · Figure S8 |
| NiFe-MOF | Ni-Fe bimetallic organic framework based on Ni(Ac)2, Fe(NO3)3 and H2NDC; exact empirical formula not reportedNi and Fe centres from Ni(Ac)2.4H2O and Fe(NO3)3.9H2O; nominal Fe:Ni precursor ratio 1:7 · 1,4-naphthalenedicarboxylic acid (H2NDC) | 2D · PristineBimetallic NiFe-MOF sheet-like nanosheets; XRD peaks at 33, 38 and 59 degrees indicate a well-crystallised framework and FT-IR/Raman show metal-carboxylate/Ni-O coordination. | 31254-31255 · 2.3 Synthesis of NiFe-MOF; 3 Results and discussion · Figures 2 and 3 |
| NiFe-MOF-CQD | Carbon quantum dot/NiFe-MOF composite; exact empirical formula not reportedNi and Fe centres in NiFe-MOF plus CQD-derived C, N, F, S and Na signals · 1,4-naphthalenedicarboxylic acid in NiFe-MOF; CQDs from p-phenylenediamine and sodium trifluoromethanesulfonate | 2D · CompositeCQD-mediated ultrathin NiFe-MOF nanosheets. TEM/AFM show CQD particles on MOF nanosheets and thickness reduced to about 10 nm; XRD/Raman/FT-IR/XPS support CQD incorporation without destroying the framework. | 31253-31255 · Abstract; 2.4 Synthesis of NiFe-MOF-CQD · Figures 1-3 |
Sample form, processing state and composition status define the context for measurements.
| Sample | Form and role | Processing and geometry | Source |
|---|---|---|---|
| CQDsresearch_0454__mat__mat_cqd | Powder · Composite Component · Derived Carbon | Hydrothermal carbonisation product; stock solution stored for synthesis and remainder dried at 80 C for measurements.height varying from 2 to 6 nm; lateral size about 3.07 nm | 31254-31255 · 2.2 Synthesis of CQDs; Results and discussion · Figure 2a,b |
| Fe-MOFresearch_0454__mat__mat_fe_mof | Nanosheet · Pristine Control · Pristine Framework | Synthesised under the NiFe-MOF procedure but with only Fe(NO3)3.9H2O in the metal solution. | 31254 · 2.3 Synthesis of NiFe-MOF · Figure S8 |
| Ni-MOFresearch_0454__mat__mat_ni_mof | Nanosheet · Pristine Control · Pristine Framework | Synthesised under the NiFe-MOF procedure but with only Ni(Ac)2.4H2O in the metal solution. | 31254 · 2.3 Synthesis of NiFe-MOF · Figure S8 |
| NiFe-MOF-CQD on glassy carbon electroderesearch_0454__mat__mat_nife_mof_cqd | Electrode · Target Sample · Composite | Catalyst ink drop-cast onto glassy carbon for three-electrode OER measurements.polished glassy carbon electrode, 0.19625 cm2 | S2 · Electrochemical measurements |
| NiFe-MOF-CQDresearch_0454__mat__mat_nife_mof_cqd | Nanosheet · Target Sample · Composite | NiFe-MOF synthesis modified by injecting 1 mL CQD stock solution into ligand solution B; subsequent processing identical to NiFe-MOF.approximately 10 nm by AFM | 31254-31255 · 2.4 Synthesis of NiFe-MOF-CQD; Results and discussion · Figure 2e,f |
| NiFe-MOF on glassy carbon electroderesearch_0454__mat__mat_nife_mof | Electrode · Pristine Control · Mixed Metal | Catalyst ink drop-cast onto glassy carbon for three-electrode OER measurements.polished glassy carbon electrode, 0.19625 cm2 | S2 · Electrochemical measurements · Figure 4 |
| NiFe-MOFresearch_0454__mat__mat_nife_mof | Nanosheet · Pristine Control · Mixed Metal | Ultrasound-assisted bottom-up synthesis; centrifuged, ethanol-rinsed and dried at 60 C for 12 h.about 150 nm by AFM | 31255 · Results and discussion · Figure 2c,d |
| NiFe-MOF-CQD/PEM/Pt-C electrolyserresearch_0454__mat__mat_nife_mof_cqd | Electrode · Target Sample · Composite | NiFe-MOF-CQD anode and Pt/C cathode inks ultrasonically sprayed on opposite sides of Nafion 115.Nafion 115 membrane catalyst-coated membrane · Nafion 115 membrane 127 um; effective membrane electrode area 58 cm2 | 31254 and 31259 · 2.5 Synthesis of PEM-WE; Results and discussion · Figure 5 |