Electrochemistry Application — Self-supporting electrocatalyst constructed from in-situ transformation of Co(OH)2 to metal-organic framework to Co/CoP/NC nanosheets for high-current-density water splitting

18 measurement groups · 56 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

cyclic voltammetry-derived double-layer capacitance

Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

CV collected between 0.425 and 0.625 V vs RHE at 50-500 mV s^-1 in 1.0 M KOH.

Atmosphere: 1.0 M KOH electrolyte, pH 14
Geometry: 0.5 cm x 1 cm self-supporting electrode in three-electrode cell
Context: CoF, Co(OH)2/CoF, CoP/CoF and Co/CoP/NC/CoF compared
Measurement source: p003 and p007 / journal pages 515 and 519 · 2.8 and 3.2 · Figure S6

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Double-layer capacitance Cdl for CoF	5.9 mF cm^-2	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Figure S6
Double-layer capacitance Cdl for Co(OH)2/CoF	8.6 mF cm^-2	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Figure S6
Double-layer capacitance Cdl for CoP/CoF	11.2 mF cm^-2	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Figure S6
Double-layer capacitance Cdl for Co/CoP/NC/CoFMarked as a best value within this paper	18.0 mF cm^-2	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Figure S6

gas collection by drainage and Faradaic-efficiency calculation

Co/CoP/NC/CoF||Co/CoP/NC/CoF electrolyzer · Electrode

Modified water electrolyzer with Nafion membrane; H2 and O2 collected at constant current of 230 mA for 1000 s.

Atmosphere: 1.0 M KOH
Geometry: Nafion-separated water electrolyzer
Context: target overall-water-splitting device
Measurement source: p010 / journal page 522 · 3.5 · Fig. 8; Figure S18

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OWS Faradaic efficiencyMarked as a best value within this paper	97.4%	—	—	Calculated From Reported Rounded Reported	p010 / journal page 522 · 3.5 · Fig. 8e
Hydrogen volume after 1000 s at 230 mA	about 26 mL	—	about	Text Approximate	p010 / journal page 522 · 3.5 · Fig. 8c-e
O2:H2 volume ratioMarked as a best value within this paper	1:2.05	—	—	Text Exact Reported	p010 / journal page 522 · 3.5 · Fig. 8e

HER electrochemical impedance spectroscopy

Impedance spectroscopy

Co/CoP/NC/CoF-550 / 6 h · Electrode

EIS at -0.15 V vs RHE from 10^-1 to 10^5 Hz in 1.0 M KOH.

Atmosphere: 1.0 M KOH
Geometry: three-electrode HER cell
Context: charge-transfer resistance comparison
Measurement source: p007 / journal page 519 · 3.2 · Fig. 4d

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
HER charge-transfer resistance RctMarked as a best value within this paper	7.5 ohm	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4d

HER growth-time optimisation LSV

Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

HER LSV in 1.0 M KOH for 0, 1, 3, 6 and 12 h MOF growth time, phosphated at 550 C.

Atmosphere: 1.0 M KOH
Geometry: self-supporting electrode
Context: optimisation of Co-MOF growth time
Measurement source: p010 · Synthetic condition optimization · Figure S9

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
HER eta10 for 0 h MOF growth	127 mV	—	—	Figure Axis Approximate	p010 · Synthetic condition optimization · Figure S9b
HER eta10 for 12 h MOF growth	72 mV	—	—	Figure Axis Approximate	p010 · Synthetic condition optimization · Figure S9b
HER eta10 for 1 h MOF growth	83 mV	—	—	Figure Axis Approximate	p010 · Synthetic condition optimization · Figure S9b
HER eta10 for 3 h MOF growth	74 mV	—	—	Figure Axis Approximate	p010 · Synthetic condition optimization · Figure S9b
HER eta10 for 6 h MOF growthMarked as a best value within this paper	64 mV	—	—	Figure Axis Approximate	p010 · Synthetic condition optimization · Figure S9b
HER eta200 for 6 h MOF growthMarked as a best value within this paper	294 mV	—	—	Figure Axis Approximate	p010 · Synthetic condition optimization · Figure S9b

HER linear sweep voltammetry

Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

HER LSV from 0.1 to -0.6 V vs RHE in 1.0 M KOH using Hg/HgO reference and graphite counter electrode.

Atmosphere: 1.0 M KOH electrolyte, pH 14
Geometry: self-supporting working electrode; same surface area controls
Context: target compared with CoF, Co(OH)2/CoF, CoP/CoF, Exo-Co/CoP/NC/CoF and Pt/C
Measurement source: p006-p007 / journal pages 518-519 · 3.2 Evaluation of hydrogen evolution performance · Fig. 4a-b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
HER overpotential at 100 mA cm^-2Marked as a best value within this paper	222 mV	—	—	SI Table Exact Reported	p017 · Table S2 · Table S2
HER overpotential at 10 mA cm^-2 for Exo-Co/CoP/NC/CoF	79 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4b
HER overpotential at 10 mA cm^-2 for Pt/C/CoF benchmarkMarked as a best value within this paper	35 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4b
HER overpotential at 10 mA cm^-2Marked as a best value within this paper	64 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4a-b; Table S1
HER overpotential at 400 mA cm^-2 for Exo-Co/CoP/NC/CoF	453 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4b
HER overpotential at 400 mA cm^-2Marked as a best value within this paper	414 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4b; Table S2

HER cycling and chronoamperometry stability

Chronoamperometry

Co/CoP/NC/CoF-550 / 6 h · Electrode

3000 CV cycles and 48 h chronoamperometry at constant overpotential of 64 mV to initially drive 10 mA cm^-2.

Atmosphere: 1.0 M KOH
Geometry: three-electrode HER cell
Context: target compared with exogenous control
Measurement source: p007 / journal page 519 · 3.2 · Fig. 4e-f; Figure S7

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
HER current-density retention after 48 h for Exo-Co/CoP/NC/CoF	61.6%	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4f
HER current-density retention after 48 hMarked as a best value within this paper	92.4%	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4f

HER Tafel analysis

Tafel and polarisation analysis

Co/CoP/NC/CoF-550 / 6 h · Electrode

Tafel slopes derived from HER polarisation curves in 1.0 M KOH.

Atmosphere: 1.0 M KOH
Geometry: three-electrode HER cell
Context: kinetics comparison among target and controls
Measurement source: p007 / journal page 519 · 3.2 · Fig. 4c

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
HER Tafel slope for Exo-Co/CoP/NC/CoF	75.3 mV dec^-1	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4c
HER Tafel slope for Co/CoP/NC/CoFMarked as a best value within this paper	49.8 mV dec^-1	—	—	Text Exact Reported	p007 / journal page 519 · 3.2 · Fig. 4c

HER phosphating-temperature optimisation LSV and EIS

Impedance spectroscopy Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

HER LSV and Nyquist plots in 1.0 M KOH for phosphating at 350, 450, 550 and 650 C.

Atmosphere: 1.0 M KOH
Geometry: self-supporting electrode
Context: optimisation of phosphating temperature
Measurement source: p011 · Synthetic condition optimization · Figure S11; Figure S12

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
HER eta10 after 350 C phosphating	110 mV	—	—	Figure Axis Approximate	p011 · Synthetic condition optimization · Figure S11b
HER eta10 after 450 C phosphating	107 mV	—	—	Figure Axis Approximate	p011 · Synthetic condition optimization · Figure S11b
HER eta10 after 550 C phosphatingMarked as a best value within this paper	64 mV	—	—	Figure Axis Approximate	p011 · Synthetic condition optimization · Figure S11b
HER eta10 after 650 C phosphating	91 mV	—	—	Figure Axis Approximate	p011 · Synthetic condition optimization · Figure S11b

mass-normalised HER and OER LSV

Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

Mass-normalised polarisation curves of Co/CoP/NC/CoF and Exo-Co/CoP/NC/CoF using active component mass loading.

Atmosphere: 1.0 M KOH
Geometry: three-electrode tests normalised by active mass loading
Context: intrinsic activity comparison with exogenous control
Measurement source: p007-p009 / journal pages 519-521 · 3.4 Mechanism analysis of catalytic activity · Fig. 6a-b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Active component mass loading for Exo-Co/CoP/NC/CoF	79 mg cm^-2	—	—	Text Exact Reported	p007 / journal page 519 · 3.4 · Fig. 6a-b
Active component mass loading for Co/CoP/NC/CoF	13 mg cm^-2	—	—	Text Exact Reported	p007 / journal page 519 · 3.4 · Fig. 6a-b
Mass-normalised HER overpotential at 100 mA cm^-2 g^-1Marked as a best value within this paper	12 mV	100 mA cm^-2 g^-1	—	Text Exact Reported	p007 / journal page 519 · 3.4 · Fig. 6a
Mass-normalised OER overpotential at 100 mA cm^-2 g^-1Marked as a best value within this paper	271 mV	100 mA cm^-2 g^-1	—	Text Exact Reported	p007 / journal page 519 · 3.4 · Fig. 6b

OER electrochemical impedance spectroscopy

Impedance spectroscopy

Co/CoP/NC/CoF-550 / 6 h · Electrode

OER EIS in 1.0 M KOH.

Atmosphere: 1.0 M KOH
Geometry: three-electrode OER cell
Context: target and controls
Measurement source: p007-p008 / journal pages 519-520 · 3.3 · Fig. 5d

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OER charge-transfer resistance RctMarked as a best value within this paper	7.0 ohm	—	—	Text Exact Reported	p008 / journal page 520 · 3.3 · Fig. 5d

OER growth-time optimisation LSV and EIS

Impedance spectroscopy Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

OER LSV and Nyquist plots in 1.0 M KOH for 0, 1, 3, 6 and 12 h MOF growth time.

Atmosphere: 1.0 M KOH
Geometry: self-supporting electrode
Context: optimisation of Co-MOF growth time
Measurement source: p012 · Synthetic condition optimization · Figure S13; Figure S14

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OER eta10 for 0 h MOF growth	323 mV	—	—	Figure Axis Approximate	p012 · Synthetic condition optimization · Figure S13b
OER eta10 for 12 h MOF growth	279 mV	—	—	Figure Axis Approximate	p012 · Synthetic condition optimization · Figure S13b
OER eta10 for 1 h MOF growth	300 mV	—	—	Figure Axis Approximate	p012 · Synthetic condition optimization · Figure S13b
OER eta10 for 3 h MOF growth	283 mV	—	—	Figure Axis Approximate	p012 · Synthetic condition optimization · Figure S13b
OER eta10 for 6 h MOF growthMarked as a best value within this paper	264 mV	—	—	Figure Axis Approximate	p012 · Synthetic condition optimization · Figure S13b
OER eta200 for 6 h MOF growthMarked as a best value within this paper	410 mV	—	—	Figure Axis Approximate	p012 · Synthetic condition optimization · Figure S13b

OER linear sweep voltammetry

Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

OER LSV from 1.0 to 2.0 V vs RHE in 1.0 M KOH using same three-electrode setup as HER.

Atmosphere: 1.0 M KOH
Geometry: self-supporting working electrode
Context: target compared with CoF, Co(OH)2/CoF, CoP/CoF, Exo-Co/CoP/NC/CoF and RuO2
Measurement source: p007-p008 / journal pages 519-520 · 3.3 Evaluation of oxygen evolution performance · Fig. 5a-b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OER overpotential at 100 mA cm^-2Marked as a best value within this paper	359 mV	—	—	Text Exact Reported	p007-p008 / journal pages 519-520 · 3.3 · Fig. 5b; Table S4
OER overpotential at 10 mA cm^-2 for RuO2 benchmarkMarked as a best value within this paper	164 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.3 · Fig. 5b
OER overpotential at 10 mA cm^-2Marked as a best value within this paper	263 mV	—	—	Text Exact Reported	p007 / journal page 519 · 3.3 · Fig. 5b; Table S3
OER overpotential at 400 mA cm^-2Marked as a best value within this paper	481 mV	—	—	Text Exact Reported	p007-p008 / journal pages 519-520 · 3.3 · Fig. 5b; Table S4

OER cycling and chronoamperometry stability

Chronoamperometry

Co/CoP/NC/CoF-550 / 6 h · Electrode

3000 CV cycles and 48 h chronoamperometry in 1.0 M KOH.

Atmosphere: 1.0 M KOH
Geometry: three-electrode OER cell
Context: target compared with exogenous control
Measurement source: p008 / journal page 520 · 3.3 · Fig. 5e-f; Figure S8

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OER current-density retention after 48 h for Exo-Co/CoP/NC/CoF	65.8%	—	—	Figure Axis Approximate	p008 / journal page 520 · Fig. 5 · Fig. 5f
OER current-density retention after 48 hMarked as a best value within this paper	90.5%	—	—	Figure Axis Approximate	p008 / journal page 520 · Fig. 5 · Fig. 5f

OER Tafel analysis

Tafel and polarisation analysis

Co/CoP/NC/CoF-550 / 6 h · Electrode

Tafel slopes derived from OER polarisation curves in 1.0 M KOH.

Atmosphere: 1.0 M KOH
Geometry: three-electrode OER cell
Context: target and controls
Measurement source: p007-p008 / journal pages 519-520 · 3.3 · Fig. 5c

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OER Tafel slope for Co/CoP/NC/CoFMarked as a best value within this paper	70.0 mV dec^-1	—	—	Text Exact Reported	p007 / journal page 519 · 3.3 · Fig. 5c

OER phosphating-temperature optimisation LSV and EIS

Impedance spectroscopy Voltammetry

Co/CoP/NC/CoF-550 / 6 h · Electrode

OER LSV and Nyquist plots in 1.0 M KOH for phosphating at 350, 450, 550 and 650 C.

Atmosphere: 1.0 M KOH
Geometry: self-supporting electrode
Context: optimisation of phosphating temperature
Measurement source: p013 · Synthetic condition optimization · Figure S15; Figure S16

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OER eta10 after 350 C phosphating	281 mV	—	—	Figure Axis Approximate	p013 · Synthetic condition optimization · Figure S15b
OER eta10 after 450 C phosphating	286 mV	—	—	Figure Axis Approximate	p013 · Synthetic condition optimization · Figure S15b
OER eta10 after 550 C phosphatingMarked as a best value within this paper	263 mV	—	—	Figure Axis Approximate	p013 · Synthetic condition optimization · Figure S15b
OER eta10 after 650 C phosphating	266 mV	—	—	Figure Axis Approximate	p013 · Synthetic condition optimization · Figure S15b

overall water splitting two-electrode LSV

Voltammetry

Co/CoP/NC/CoF||Co/CoP/NC/CoF electrolyzer · Electrode

Co/CoP/NC/CoF used as both anode and cathode in 1.0 M KOH; compared with Pt/C/CoF||RuO2/CoF.

Atmosphere: 1.0 M KOH
Geometry: two-electrode electrolyzer
Context: target bifunctional device versus noble-metal benchmark
Measurement source: p009-p010 / journal pages 521-522 · 3.5 Evaluation of overall water splitting and applications · Fig. 7a

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OWS cell voltage at 200 mA cm^-2 for Pt/C\|\|RuO2 benchmark	2.18 V	—	—	Text Exact Reported	p009-p010 / journal pages 521-522 · 3.5 · Fig. 7a
OWS cell voltage at 10 mA cm^-2Marked as a best value within this paper	1.56 V	—	—	Text Exact Reported	p009-p010 / journal pages 521-522 · 3.5 · Fig. 7a; Table S5
OWS cell voltage at 100 mA cm^-2	1.74 V	—	—	Figure Axis Approximate	p009 / journal page 521 · Fig. 7 · Fig. 7a
OWS cell voltage at 200 mA cm^-2Marked as a best value within this paper	1.88 V	—	—	Text Exact Reported	p009-p010 / journal pages 521-522 · 3.5 · Fig. 7a

overall water splitting chronoamperometry

Chronoamperometry

Co/CoP/NC/CoF||Co/CoP/NC/CoF electrolyzer · Electrode

Current-density time-dependent tests at 10, 20, 50, 100, 200 and 400 mA cm^-2 for 12 h each.

Atmosphere: 1.0 M KOH
Geometry: two-electrode electrolyzer
Context: target device versus Pt/C||RuO2 benchmark
Measurement source: p009-p010 / journal pages 521-522 · 3.5 · Fig. 7c

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
OWS stability duration at each tested current densityMarked as a best value within this paper	12 h at 10, 20, 50, 100, 200, and 400 mA cm^-2	—	—	Text Exact Reported	p010 / journal page 522 · 3.5 · Fig. 7c

solar-powered water-electrolyzer demonstration

Co/CoP/NC/CoF||Co/CoP/NC/CoF electrolyzer · Electrode

Commercial solar panel replaced the DC power supply and drove HER/OER on self-supporting electrodes.

Atmosphere: alkaline water-splitting conditions
Geometry: solar cell panel connected to water electrolyzer
Context: application demonstration for target device
Measurement source: p010 / journal page 522 · 3.5 · Fig. 8f-g

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Solar-powered OWS demonstration	commercial solar cell panel drove HER and OER with massive hydrogen and oxygen bubbles	—	—	Text Qualitative	p010 / journal page 522 · 3.5 · Fig. 8f-g