Electrochemistry Application — Vertical Conductive Metal–Organic Framework Single-Crystalline Nanowire Arrays for Efficient Electrocatalytic Hydrogen Evolution

8 measurement groups · 44 results

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

H2 bubble slide-angle test and in situ optical/confocal microscopy during HER

Ag-MOF-NWs · Single Crystal

H2 bubble release rate and bubble size monitored using microscope with high-speed camera at same voltage; in situ comparison at -0.4 V.

Geometry: electrode surfaces coupled to confocal microscope/electrochemical workstation
Context: pristine morphology comparison
Measurement source: Supplementary Methods 1.6 Measurement of electrocatalytic microdevice

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
H2 bubble slide behaviour Ag-MOF-Film	bubbles adhered to the surface	—	—	Text Qualitative	7 · Superhydrophilic and Superaerophobic Structure · Figure 7a
H2 bubble slide release time Ag-MOF-NWsMarked as a best value within this paper	rapidly released within 1.5 s	—	—	Text Rounded Reported	7 · Superhydrophilic and Superaerophobic Structure · Figure 7b
Ag-MOF-Film bubble generation observation	bubbles emerging slowly after 2 s	—	—	Text Rounded Reported	7 · Superhydrophilic and Superaerophobic Structure · Figure 7c
Ag-MOF-NWs bubble generation onset observation	many bubbles after 0.3 s	—	—	Text Rounded Reported	7 · Superhydrophilic and Superaerophobic Structure · Figure 7d
In situ bubble monitoring voltage	-0.4 V	—	—	Text Exact Reported	7 · Superhydrophilic and Superaerophobic Structure · Figure 7c,d

Double-layer capacitance from cyclic voltammetry

Voltammetry

Ag-MOF-NWs · Single Crystal

Cyclic voltammetry at scan rates 50-150 mV s-1 in the voltage window 0.4-0.5 V for Cdl/ECSA comparison.

Geometry: on-chip micro-electrochemical device
Context: pristine morphology series
Measurement source: Supplementary Methods 1.6 Measurement of electrocatalytic microdevice

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Double-layer capacitance Ag-MOF-Film	0.023 mF cm-2	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5h
Double-layer capacitance Ag-MOF-MWs	0.14 mF cm-2	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5h
Double-layer capacitance Ag-MOF-NWsMarked as a best value within this paper	0.31 mF cm-2	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5h

Electrochemical impedance spectroscopy Nyquist analysis

Impedance spectroscopy

Ag-MOF-NWs · Single Crystal

EIS at overpotential of 100 mV versus RHE over 10^-2 to 10^6 Hz in 0.5 M H2SO4 droplet microdevice.

Geometry: on-chip micro-electrochemical device
Context: pristine morphology series
Measurement source: Supplementary Methods 1.6 Measurement of electrocatalytic microdevice

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Charge-transfer resistance Rct Ag-MOF-Film	312.5 ohm	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5i
Charge-transfer resistance Rct Ag-MOF-MWs	230.5 ohm	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5i
Charge-transfer resistance Rct Ag-MOF-NWsMarked as a best value within this paper	40.1 ohm	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5i

HER LSV and Tafel analysis on on-chip micro-electrochemical device

Voltammetry Tafel and polarisation analysis

Ag-MOF-NWs · Single Crystal

Three-electrode HER test in 0.5 M H2SO4 droplet at ambient temperature; Ag-MOF connected to gold pad working electrode, Ag/AgCl reference, graphite rod counter; LSV scan rate 5 mV s-1.

Geometry: Cr/Au layer 5/30 nm on 2 x 2 cm silicon wafer; SU8 patterned catalytic window 100 x 200 um.
Context: pristine morphology series
Measurement source: Supplementary Methods 1.6 Measurement of electrocatalytic microdevice

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Au electrode layer thickness	30 nm	—	—	Text Exact Reported	Supplementary Methods 1.4 Fabrication of electrocatalytic microdevice
Cr adhesion layer thickness	5 nm	—	—	Text Exact Reported	Supplementary Methods 1.4 Fabrication of electrocatalytic microdevice
Microdevice catalytic window dimensions	100 x 200 um	—	—	Text Exact Reported	Supplementary Methods 1.4 Fabrication of electrocatalytic microdevice
Table S2 this-work overpotential at 10 mA cm-2Marked as a best value within this paper	105 mV at 10 mA cm-2	10 mA cm-2	—	SI Table Exact Reported	14 · Supplementary Tables · Table S2
Table S2 this-work Tafel slopeMarked as a best value within this paper	66 mV dec-1	—	—	SI Table Exact Reported	14 · Supplementary Tables · Table S2
Tafel slope Ag-MOF-Film	108 mV dec-1	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5c
Tafel slope Ag-MOF-MWs	85 mV dec-1	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5c
Tafel slope Ag-MOF-NWsMarked as a best value within this paper	66 mV dec-1	—	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5c

HER overpotential at specified current densities

Ag-MOF-NWs · Single Crystal

HER values measured in the same three-electrode 0.5 M H2SO4 droplet microdevice; LSV scan rate 5 mV s-1 at ambient temperature.

Geometry: On-chip micro-electrochemical device with 100 x 200 um catalytic window.
Context: pristine morphology series
Measurement source: Supplementary Methods 1.6 Measurement of electrocatalytic microdevice

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Overpotential at 1000 mA cm-2 Ag-MOF-MWs	518 mV at 1000 mA cm-2	1000 mA cm-2	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 1000 mA cm-2 Ag-MOF-NWsMarked as a best value within this paper	275 mV at 1000 mA cm-2	1000 mA cm-2	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 100 mA cm-2 Ag-MOF-Film	510 mV at 100 mA cm-2	100 mA cm-2	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 100 mA cm-2 Ag-MOF-MWs	378 mV at 100 mA cm-2	100 mA cm-2	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 100 mA cm-2 Ag-MOF-NWsMarked as a best value within this paper	175 mV at 100 mA cm-2	100 mA cm-2	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 10 mA cm-2 Ag-MOF-Film	359 mV at 10 mA cm-2	10 mA cm-2	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 10 mA cm-2 Ag-MOF-MWs	288 mV at 10 mA cm-2	10 mA cm-2	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 10 mA cm-2 Ag-MOF-NWsMarked as a best value within this paper	105 mV at 10 mA cm-2	10 mA cm-2	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 500 mA cm-2 Ag-MOF-Film	773 mV at 500 mA cm-2	500 mA cm-2	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 500 mA cm-2 Ag-MOF-MWs	462 mV at 500 mA cm-2	500 mA cm-2	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5d
Overpotential at 500 mA cm-2 Ag-MOF-NWsMarked as a best value within this paper	235 mV at 500 mA cm-2	500 mA cm-2	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5d

Mass current density at specified overpotentials

Ag-MOF-NWs · Single Crystal

HER values measured in the same three-electrode 0.5 M H2SO4 droplet microdevice; LSV scan rate 5 mV s-1 at ambient temperature.

Geometry: On-chip micro-electrochemical device with 100 x 200 um catalytic window.
Context: pristine morphology series
Measurement source: Supplementary Methods 1.6 Measurement of electrocatalytic microdevice

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Mass current density at 100 mV Ag-MOF-Film	0.3 A cm-2 mg-1 at 100 mV	100 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 100 mV Ag-MOF-MWs	0.4 A cm-2 mg-1 at 100 mV	100 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 100 mV Ag-MOF-NWsMarked as a best value within this paper	2 A cm-2 mg-1 at 100 mV	100 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 200 mV Ag-MOF-Film	0.5 A cm-2 mg-1 at 200 mV	200 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 200 mV Ag-MOF-MWs	0.8 A cm-2 mg-1 at 200 mV	200 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 200 mV Ag-MOF-NWsMarked as a best value within this paper	51 A cm-2 mg-1 at 200 mV	200 mV	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 300 mV Ag-MOF-Film	1 A cm-2 mg-1 at 300 mV	300 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 300 mV Ag-MOF-MWs	6 A cm-2 mg-1 at 300 mV	300 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f
Mass current density at 300 mV Ag-MOF-NWsMarked as a best value within this paper	341 A cm-2 mg-1 at 300 mV	300 mV	—	Figure Axis Rounded Reported	6 · Electrocatalytic HER Performances · Figure 5f

HER stability after cyclic voltammetry and acid soaking

Voltammetry

Ag-MOF-NWs · Single Crystal

1000 CV cycles, post-HER SEM/Raman/XPS, and Ag-BHT XRD after soaking in 0.5 M H2SO4 for 24 h.

Geometry: on-chip micro-electrochemical device; acid-soaked sample
Context: pristine target sample
Measurement source: Supplementary Figure S15 note · Figure S15

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
XRD after acid soaking	XRD pattern does not change significantly after soaking in 0.5 M H2SO4 for 24 h	—	—	Text Qualitative	6 · Electrocatalytic HER Performances · Figure S19
LSV after 1000 CV cycles	only a small change in voltage	—	—	Text Qualitative	5 · Electrocatalytic HER Performances · Figure S15

Turnover frequency calculated from estimated active-site number

Ag-MOF-NWs · Single Crystal

TOF calculated from active sites estimated by CV from -0.3 to 0 V in 1.0 M PBS at pH 7; current density-time curves integrated and divided by 2F for reversible one-electron redox process.

Geometry: on-chip micro-electrochemical device
Context: pristine morphology series
Measurement source: Supplementary Methods 1.7 Calculation of TOF

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
TOF at 150 mV Ag-MOF-Film	0.0021 s-1 at 150 mV	150 mV	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5g
TOF at 150 mV Ag-MOF-MWs	0.0061 s-1 at 150 mV	150 mV	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5g
TOF at 150 mV Ag-MOF-NWsMarked as a best value within this paper	0.14 s-1 at 150 mV	150 mV	—	Text Exact Reported	5 · Electrocatalytic HER Performances · Figure 5g