Electrochemistry Application — Electrocatalytic Hydrogen Evolution from a Cobaloxime-Based Metal-Organic Framework Thin Film

8 measurement groups · 31 results

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

Control controlled-potential electrolysis

Molecular cobaloxime linker solution · Unknown

Molecular cobaloxime linker in aqueous acetate buffer pH 5.3 at -0.43 V vs RHE; blank control also reported.

Geometry: Graphite rod electrode, about 1 cm2
Context: molecular control compared with MOF electrode
Measurement source: S35 · Electrocatalysis by UU-100(Co)|GC · Figure S46

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Blank glassy carbon HER faradaic yield	45(+/-5)%	0.45 fraction	+/- 5%	Caption Exact Reported	S34 · Figure caption · Figure S45
Molecular linker homogeneous HER hydrogen amount	15.2 +/- 0.06 umol H2	—	+/- 0.06 umol	Caption Exact Reported	S35 · Figure caption · Figure S46
Molecular linker homogeneous HER faradaic efficiency	90%	0.9 fraction	—	Caption Rounded Reported	S35 · Figure caption · Figure S46

Chronoamperometry

UU-100(Co)|FTO thin-film electrode · Electrode

Potential steps between -0.05 V and -1.50 V in DMF/0.1 M LiClO4; 120 s at each potential.

Atmosphere: Argon sparged
Geometry: UU-100(Co)|FTO working electrode
Context: pristine framework thin film on FTO
Measurement source: 15945 · Electrochemical Characterization of UU-100(Co)|FTO · Figures S27-S28

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Electrochemically addressable cobaloxime fractionMarked as a best value within this paper	54 +/- 15%	0.54 fraction	+/- 15%	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Figures S27-S28
Electroactive cobaloxime surface concentration, oxidative step	6.8 x 10-8 mol cm-2	—	—	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Figures S27-S28
Electroactive cobaloxime surface concentration, reductive step	7.0 x 10-8 mol cm-2	—	—	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Figures S27-S28
Total cobalt surface concentration by ICP-OES	12.2 x 10-8 mol cm-2	—	—	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Table S4

Cyclic voltammetry

Voltammetry

UU-100(Co)|FTO thin-film electrode · Electrode

DMF containing 0.1 M LiClO4; potentials vs Fc+/0; scan rates 10-250 mV/s in related figures.

Atmosphere: Argon sparged for 10 min before electrochemistry
Geometry: Three-electrode cell with MOF film working electrode, Ag/AgNO3 reference, Pt wire counter electrode
Context: pristine framework thin film on FTO
Measurement source: 15945 · Electrochemical Characterization of UU-100(Co)|FTO · Figure 4A; Figures S26-S31

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
CoII/I E1/2Marked as a best value within this paper	E1/2 = -1.28 V vs Fc+/0	—	—	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Figure 4A
CoII/I anodic peak potential	Ep,a = -1.16 V vs Fc+/0	—	—	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Figure 4A
CoII/I cathodic peak potential	Ep,c = -1.40 V vs Fc+/0	—	—	Text Exact Reported	15945 · Electrochemical Characterization of UU-100(Co)\|FTO · Figure 4A
log(ip) vs log(scan rate) slope, fast scan-rate region	0.51	—	—	Text Rounded Reported	15946 · Electrochemical Characterization of UU-100(Co)\|FTO · Figure S31
log(ip) vs log(scan rate) slope, slow scan-rate region	0.92	—	—	Text Rounded Reported	15946 · Electrochemical Characterization of UU-100(Co)\|FTO · Figure S31
Calculated switching scan rate threshold	100(+/-25) mV s-1	0.1 V s-1	+/- 25 mV s-1	Calculated From Reported Exact Reported	15946 · Electrochemical Characterization of UU-100(Co)\|FTO · Figures S30-S31

Long-term controlled potential electrolysis

UU-100(Co)|GC thin-film electrode · Electrode

Acetate buffer at pH 4; -0.45 V vs RHE for 18 h; H2 quantified by gas chromatography.

Atmosphere: Argon sparged
Geometry: UU-100(Co)|GC electrode in H-cell
Context: pristine framework on glassy carbon
Measurement source: 15948 · Electrocatalytic HER by UU-100(Co)|GC · Figure S37

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Faradaic efficiency for H2 over 18 h	79 +/- 3%	0.79 fraction	+/- 3%	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure S37
Hydrogen evolved over 18 h, areal	309 umol H2 cm-2	—	—	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure S37
Average formal turnover frequency over 18 h	TOFCo = 1171 h-1	—	—	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure S37
Turnover number based on electroactive cobalt over 18 hMarked as a best value within this paper	TONCo = 20875	—	—	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure S37

Controlled potential electrolysis

UU-100(Co)|GC thin-film electrode · Electrode

0.1 M NaClO4 / 0.2 M acetate buffer at pH 4; -0.45 V vs RHE for 5 h; H2 quantified by gas chromatography.

Atmosphere: Argon sparged
Geometry: Two-compartment H-cell, glass frit, Pt coil counter electrode; geometric electrode area 0.5 cm2
Context: pristine framework on glassy carbon
Measurement source: 15947 · Electrocatalytic HER by UU-100(Co)|GC · Figure 6A

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Charge passed over 5 h	29 C cm-2	—	—	Text Exact Reported	15947 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A
Controlled electrolysis potential	-0.45 V vs RHE	—	—	Text Exact Reported	15947 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A
Stable current density during 5 h electrolysis	~ -1.7 mA cm-2	—	approximately	Text Approximate	15947 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A
Faradaic efficiency for H2 over 5 hMarked as a best value within this paper	84 +/- 5%	0.84 fraction	+/- 5%	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A
Hydrogen evolved over 5 h	66 umol H2	—	—	Text Exact Reported	15947-15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A
Average formal turnover frequency over 5 h	TOFCo = 1650 h-1	—	—	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A
Turnover number based on electroactive cobalt over 5 h	TONCo = 8250	—	—	Text Exact Reported	15948 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 6A

Cyclic voltammetry

Voltammetry

UU-100(Co)|GC thin-film electrode · Electrode

DMF electrolyte; UU-100(Co)|GC at several scan rates.

Atmosphere: Argon sparged
Geometry: UU-100(Co)|GC working electrode
Context: pristine framework on glassy carbon
Measurement source: 15946 · Electrocatalytic HER by UU-100(Co)|GC · Figure 5A; Figure S36

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Electrochemical accessibility of cobalt centres on GC	31%	0.31 fraction	—	Text Rounded Reported	15946 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 5A
Electroactive cobaloxime surface concentration on GCMarked as a best value within this paper	~1.6 x 10-8 mol cm-2	—	approximately	Text Approximate	15946 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 5A

Linear sweep voltammetry and Tafel analysis

Voltammetry Tafel and polarisation analysis

UU-100(Co)|GC thin-film electrode · Electrode

Acetate buffer at pH 4; LSV recorded at 20 mV/s; potentials vs RHE.

Atmosphere: Argon sparged
Geometry: UU-100(Co)|GC working electrode
Context: pristine framework on glassy carbon
Measurement source: 15947 · Electrocatalytic HER by UU-100(Co)|GC · Figure 5B-C

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Exchange current density	~10^-4.2 A cm-2	—	approximately	Text Approximate	15947 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 5C
HER catalytic onset potential	~ -0.15 V vs RHE	—	approximately	Text Approximate	15947 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 5B
Tafel slopeMarked as a best value within this paper	250 mV dec-1	—	—	Text Exact Reported	15947 · Electrocatalytic HER by UU-100(Co)\|GC · Figure 5C

Solution-phase cyclic voltammetry

Voltammetry

Molecular cobaloxime linker solution · Unknown

Cobaloxime linker in DMF, referenced to Fc+/0; 0.1 M electrolyte; GC disk working electrode.

Atmosphere: Argon sparged
Geometry: Solution-phase three-electrode cell
Context: molecular control
Measurement source: S22 · Electrochemical analysis · Figure S24

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Molecular linker irreversible CoIII/II reduction	~ -0.95 V vs Fc+/0	—	approximately	Text Approximate	S22 · Electrochemical analysis · Figure S24
Molecular linker CoII/I E1/2Marked as a best value within this paper	E1/2 = -1.13 V vs Fc+/0	—	—	Text Exact Reported	S22 · Electrochemical analysis · Figure S24