Spectroscopy — Nano UiO-66 and UiO-66-NH2 MOFs as Bifunctional Electrocatalysts for Water-Splitting: A Comparative Study

6 measurement groups · 32 results

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

FTIR spectroscopy in ATR mode (SHIMADZU IRTRACER 100)

Infrared spectroscopy

UiO-66 powder, labelled U · Powder

500-4500 cm-1 spectral range.

Context: pristine UiO-66 powder
Measurement source: 3-4 · 2.3 Materials characterization; 3.2 FTIR · Fig. 2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
asymmetric COO- stretching band	1560 cm-1	—	—	Text Rounded Reported	4 · 3.2 FTIR · Fig. 2
C=O stretching band	1650 cm-1	—	—	Text Rounded Reported	4 · 3.2 FTIR · Fig. 2
O-H vibration band	3340 cm-1	—	—	Text Rounded Reported	4 · 3.2 FTIR · Fig. 2
symmetric COO- stretching band	1370 cm-1	—	—	Text Rounded Reported	4 · 3.2 FTIR · Fig. 2

FTIR spectroscopy in ATR mode (SHIMADZU IRTRACER 100)

Infrared spectroscopy

UiO-66-NH2 powder, labelled U-N · Powder

500-4500 cm-1 spectral range.

Context: pristine amino-functionalised UiO-66-NH2 powder
Measurement source: 4 · 3.2 FTIR · Fig. 2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
C-N stretching band from amine functionality	1250 cm-1	—	—	Text Rounded Reported	4 · 3.2 FTIR · Fig. 2

UV-Vis absorbance spectroscopy (SHIMADZU UV 5600 PLUS) with Tauc analysis

UV-visible and optical absorption spectroscopy

UiO-66 powder, labelled U · Powder

Absorbance recorded across 200-800 nm; indirect band gap from (alpha hv)^1/2 Tauc plot.

Context: pristine UiO-66 powder
Measurement source: 4 · 3.3 UV-Vis · Fig. 3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
indirect optical band gap	3.2 eV	—	—	Text Rounded Reported	4 · 3.3 UV-Vis · Fig. 3

UV-Vis absorbance spectroscopy (SHIMADZU UV 5600 PLUS) with Tauc analysis

UV-visible and optical absorption spectroscopy

UiO-66-NH2 powder, labelled U-N · Powder

Absorbance recorded across 200-800 nm; indirect band gap from (alpha hv)^1/2 Tauc plot.

Context: pristine amino-functionalised UiO-66-NH2 powder
Measurement source: 4 · 3.3 UV-Vis · Fig. 3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
indirect optical band gapMarked as a best value within this paper	2.4 eV	—	—	Text Rounded Reported	4 · 3.3 UV-Vis · Fig. 3

XPS (ESCALAB 250 XI Thermo Scientific, Al K alpha, 650 um spot)

X-ray photoelectron spectroscopy

UiO-66 powder, labelled U · Powder

Survey, high-resolution Zr 3d, C 1s, O 1s, and valence-band spectra.

Context: pristine UiO-66 powder
Measurement source: 3, 5-7 · 2.3 Materials characterization; 3.6 XPS · Fig. 6

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
C 1s component binding energies	282.5 eV (C=C or C-C), 283.7 eV (C-O), 286.5 eV (C=O)	—	—	Text Exact Reported	5-6 · 3.6 XPS · Fig. 6d
C 1s atomic composition	63.47%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a
calculated conduction-band edge	2.18 eV	—	—	Calculated From Reported Exact Reported	6 · 3.6 XPS · Fig. 6f
O 1s component binding energies	529.7 eV lattice oxygen in ZrO2 clusters; 527.7 eV defect oxygen / reduced oxygen / non-lattice hydroxyl ions	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6e
O 1s atomic composition	31.92%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a
valence band maximum	-1.02 eV	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6f
Zr 3d3/2 binding energy	182.4 eV	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6c
Zr 3d5/2 binding energy	180.7 eV	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6c
Zr 3d atomic composition	4.61%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a

XPS (ESCALAB 250 XI Thermo Scientific, Al K alpha, 650 um spot)

X-ray photoelectron spectroscopy

UiO-66-NH2 powder, labelled U-N · Powder

Survey, high-resolution N 1s, Zr 3d, C 1s, O 1s, and valence-band spectra.

Context: pristine amino-functionalised UiO-66-NH2 powder
Measurement source: 5-7 · 3.6 XPS · Fig. 6

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
C 1s most-intense peak shift	3.6 eV shift between the most intense C 1s peaks of U and U-N	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6d
O 1s binding-energy shift	~5.5 eV shift	—	~	Text Approximate	6 · 3.6 XPS · Fig. 6e
C 1s component binding energies	285.4 eV (C-N or C-H), 286.8 eV (C=O), 289.5 eV (COOH or C=O), 292.8 eV (pi-pi transitions)	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6d
C 1s atomic composition	69.09%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a
calculated conduction-band edgeMarked as a best value within this paper	0.61 eV	—	—	Calculated From Reported Exact Reported	6 · 3.6 XPS · Fig. 6f
N 1s peak for protonated amine	401.4 eV attributed to -NH3+ groups	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6b
N 1s peak for oxidized nitrogen species	404.2 eV attributed to oxidized nitrogen (NOx) species	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6b
N 1s peak for nitro groups	406.1 eV assigned to oxidized nitrogen (-NO2)	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6b
N 1s atomic compositionMarked as a best value within this paper	2.79%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a
O 1s component binding energies	535.2 eV adsorbed water/surface hydroxyl groups; 533.1 eV oxygen atoms in C-OH-type functional groups	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6e
O 1s atomic composition	26.57%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a
valence band maximumMarked as a best value within this paper	-1.79 eV	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6f
Zr 3d3/2 binding energy	189.6 eV	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6c
Zr 3d5/2 binding energy	187.2 eV	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6c
Zr 3d atomic composition	1.55%	—	—	Text Exact Reported	6 · 3.6 XPS · Fig. 6a
Zr 3d binding-energy shift	6.8 eV higher binding energy shift in U-N	—	—	Text Exact Reported	5 · 3.6 XPS · Fig. 6c