Electrochemistry Application — Hollow Cobalt-Based Bimetallic Sulfide Polyhedra for Efficient All-pH-Value Electrochemical and Photocatalytic Hydrogen Evolution

8 measurement groups · 24 results

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

Glassy-carbon electrode catalyst ink preparation

hollow Zn0.30Co2.70S4 · Powder

4 mg catalyst in 1 mL water-isopropanol (3:1) with 50 uL 5 wt % Nafion; sonicated 3 h; 5 uL ink on 3 mm glassy-carbon electrode; loading 0.285 mg cm-2; top-coated with 3 uL 5 wt % Nafion.

Geometry: 3 mm diameter glassy carbon electrode; catalyst loading 0.285 mg cm-2
Context: same electrode fabrication for sulphide catalysts
Measurement source: 1360 · 2.4. Electrocatalytic HER

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source

Chronoamperometry/cycling and gas chromatography H2 quantification

Chronoamperometry

hollow Zn0.30Co2.70S4 · Powder

Electrochemical H2 production at ca. 25 mA cm-2 and stability at eta = -100 mV over 60 h; evolved H2 monitored by GC.

Atmosphere: Ar carrier for GC; electrochemical cell conditions as HER measurement
Geometry: glassy-carbon electrode
Context: Zn0.30Co2.70S4 stability compared with Co3S4
Measurement source: 1363 · 3.3. Superior Electrocatalytic Performance in Acidic Media · Figure 5c,d; Figures S10-S11

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Co3S4 current retention after 10 h	about 75%	—	about	Text Approximate	1363 · 3.3 · Figure S11
Zn0.30Co2.70S4 current retention over 60 hMarked as a best value within this paper	J60/J0 = 95%	—	—	Figure Axis Rounded Reported	S18 · Figure S11 · Figure S11
Zn0.30Co2.70S4 faradaic yieldMarked as a best value within this paper	about 100%	—	about	Text Approximate	1363 · 3.3 · Figure 5c
Zn0.30Co2.70S4 electrochemical H2 generation rateMarked as a best value within this paper	49.7 umol h-1	—	—	Text Exact Reported	1363 · 3.3 · Figure 5c

Linear sweep voltammetry HER polarisation

Voltammetry

hollow Zn0.30Co2.70S4 · Powder

0.5 M H2SO4, pH 0; three-electrode setup; graphite counter, SCE reference calibrated to RHE; scan rate 5 mV s-1.

Atmosphere: H2-saturated electrolyte for reference calibration
Geometry: glassy-carbon electrode, 0.285 mg cm-2 catalyst loading
Context: bimetallic sulphides compared with Co3S4 and Pt/C
Measurement source: 1362 · 3.3. Superior Electrocatalytic Performance in Acidic Media · Figure 5a

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Co3S4 overpotential at 10 mA cm-2 in 0.5 M H2SO4	380 mV	—	—	Text Exact Reported	1362 · 3.3 · Figure 5a
Cu0.30Co2.70S4 overpotential at 10 mA cm-2 in 0.5 M H2SO4	243 mV	—	—	Text Exact Reported	1362 · 3.3 · Figure 5a
Ni0.30Co2.70S4 overpotential at 10 mA cm-2 in 0.5 M H2SO4	186 mV	—	—	Text Exact Reported	1362 · 3.3 · Figure 5a
Zn0.30Co2.70S4 overpotential at 10 mA cm-2 in 0.5 M H2SO4Marked as a best value within this paper	80 mV	—	—	Text Exact Reported	1362 · 3.3 · Figure 5a
Zn0.30Co2.70S4 overpotential at 100 mA cm-2 in 0.5 M H2SO4Marked as a best value within this paper	129 mV	—	—	Text Exact Reported	1362 · 3.3 · Figure 5a
milled Zn0.30Co2.70S4 overpotential at 10 mA cm-2 in 0.5 M H2SO4	eta10 of 125 mV	—	—	Text Exact Reported	1363 · 3.3 · Figure S12; Figure 5a

Linear sweep voltammetry HER polarisation

Voltammetry

hollow Zn0.30Co2.70S4 · Powder

1 M KOH, pH 14, scan rate 5 mV s-1.

Geometry: glassy-carbon electrode, 0.285 mg cm-2 catalyst loading
Context: Zn0.30Co2.70S4 all-pH HER performance
Measurement source: 1359 · Abstract

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Zn0.30Co2.70S4 overpotential at 10 mA cm-2 in 1 M KOH	85 mV	—	—	Text Exact Reported	1359 · Abstract · Figure 7; Table S4
Zn0.30Co2.70S4 overpotential at 100 mA cm-2 in 1 M KOH	136 mV	—	—	Text Exact Reported	1359 · Abstract · Figure 7; Table S4

Linear sweep voltammetry HER polarisation

Voltammetry

hollow Zn0.30Co2.70S4 · Powder

0.1 M phosphate buffer, pH 7, scan rate 5 mV s-1.

Geometry: glassy-carbon electrode, 0.285 mg cm-2 catalyst loading
Context: Zn0.30Co2.70S4 all-pH HER performance
Measurement source: 1359 · Abstract

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Zn0.30Co2.70S4 overpotential at 10 mA cm-2 in phosphate buffer	90 mV	—	—	Text Exact Reported	1359 · Abstract · Figure 7; Table S4
Zn0.30Co2.70S4 overpotential at 100 mA cm-2 in phosphate buffer	144 mV	—	—	Text Exact Reported	1359 · Abstract · Figure 7; Table S4

Photocatalytic HER with Eosin Y photosensitiser

hollow Zn0.30Co2.70S4 · Powder

Visible light >400 nm; 1.0 mg sulphide or Pt/C and 3.5 mg Eosin Y in 20 mL TEOA-H2O (5%, v/v); Ar deaeration 30 min; H2 by GC.

Atmosphere: Ar-deaerated reaction mixture
Geometry: closed 50 mL flask; 300 W Xe lamp
Context: Zn0.30Co2.70S4 cocatalyst compared with Pt/C
Measurement source: 1360, 1364 · 2.5 and 3.6 · Figure 7e

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
EY-sensitised Pt/C photocatalytic H2 evolution rateMarked as a best value within this paper	188.7 umol h-1	—	—	Text Exact Reported	1364 · 3.6 · Figure 7e
EY-sensitised Zn0.30Co2.70S4 photocatalytic H2 evolution rate	155.2 umol h-1	—	—	Text Exact Reported	1364 · 3.6 · Figure 7e

Photocatalytic HER with TiO2 or C3N4 semiconductor

Zn0.30Co2.70S4-TiO2 photocatalytic mixture · Powder

0.2 mg sulphide or in situ photodeposited Pt with 20 mg TiO2 or C3N4 in 20 mL CH3OH(TEOA)-H2O (5%, v/v); UV for TiO2 and visible light for C3N4.

Atmosphere: Ar-deaerated reaction mixture
Geometry: closed 50 mL flask; 300 W Xe lamp
Context: Zn0.30Co2.70S4 as cocatalyst in semiconductor photocatalysis
Measurement source: 1360, 1364 · 2.5 and 3.6 · Figure 7f

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Pt-C3N4 photocatalytic HER rateMarked as a best value within this paper	581.3 umol h-1	—	—	Figure Axis Rounded Reported	1364 · 3.6 · Figure 7f
Zn0.30Co2.70S4-C3N4 photocatalytic HER rate	545.1 umol h-1	—	—	Figure Axis Rounded Reported	1364 · 3.6 · Figure 7f
Pt-TiO2 photocatalytic HER rateMarked as a best value within this paper	1200.6 umol h-1	—	—	Figure Axis Rounded Reported	1364 · 3.6 · Figure 7f
Zn0.30Co2.70S4-TiO2 photocatalytic HER rate	1005.3 umol h-1	—	—	Figure Axis Rounded Reported	1364 · 3.6 · Figure 7f

Tafel analysis and exchange-current extrapolation

Tafel and polarisation analysis

hollow Zn0.30Co2.70S4 · Powder

Tafel plots from HER polarisation curves in 0.5 M H2SO4; exchange current density from extrapolation.

Geometry: glassy-carbon electrode, 0.285 mg cm-2 catalyst loading
Context: Zn0.30Co2.70S4 compared with Co3S4 and Pt/C
Measurement source: 1362-1363 · 3.3. Superior Electrocatalytic Performance in Acidic Media · Figure 5b; Figure S9

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Co3S4 exchange current density	0.025 mA cm-2	—	—	Text Exact Reported	1363 · 3.3 · Figure S9
Zn0.30Co2.70S4 exchange current densityMarked as a best value within this paper	0.15 mA cm-2	—	—	Text Exact Reported	1362-1363 · 3.3 · Figure S9
Co3S4 Tafel slope	~85.3 mV dec-1	—	~	Text Approximate	1362 · 3.3 · Figure 5b
Zn0.30Co2.70S4 Tafel slope	~47.5 mV dec-1	—	~	Text Approximate	1362 · 3.3 · Figure 5b