Spectroscopy — Dissecting π-conjugated covalent-coupling over conductive MOFs toward efficient two-electron oxygen reduction

5 measurement groups · 32 results

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

Fourier-transformed EXAFS / FT-XAFS fitting

X-ray absorption spectroscopy

Cu-HHTP nanorod powder · Powder

Cu K-edge EXAFS fitting in R-space; SI Table S2 reports Cu-O path fitted parameters for Cu-HHTP.

Geometry: Ex situ FT-XAFS
Context: target pristine conductive MOF
Measurement source: S27 · XAFS data analysis · Figure S6; Table S2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Nearest Cu-O shell coordination number	3.8(+/-0.1)	—	+/-0.1	SI Table Exact Reported	S27 · Supporting Tables · Table S2
Nearest Cu-O shell energy shift, ex situ	5.6(+/-0.3) eV	—	+/-0.3 eV	SI Table Exact Reported	S27 · Supporting Tables · Table S2
Nearest Cu-O shell bond distance, ex situ	1.94(+/-0.02) A	—	+/-0.02 A	SI Table Exact Reported	S27 · Supporting Tables · Table S2
Dominant FT-XAFS Cu-O peak position	about 1.5 A	—	—	Text Approximate	3 · 3.1 Morphology and structure characterization · Fig. 1f
Nearest Cu-O shell EXAFS R-factor, ex situ	0.006	—	—	SI Table Exact Reported	S27 · Supporting Tables · Table S2
Nearest Cu-O shell Debye-Waller factor, ex situ	6.8(+/-0.2) x 10^-3 A^2	—	+/-0.2 x 10^-3 A^2	SI Table Exact Reported	S27 · Supporting Tables · Table S2

Cu K-edge XANES

X-ray absorption spectroscopy

Cu-HHTP nanorod powder · Powder

Synchrotron X-ray absorption spectroscopy used to identify local coordination environment; compared with Cu foil, Cu2O and CuO references.

Geometry: Ex situ Cu K-edge XANES
Context: target pristine conductive MOF
Measurement source: 3 · 3.1 Morphology and structure characterization · Fig. 1e; Fig. S4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Average Cu oxidation state	1.8	—	—	Text Exact Reported	3 · 3.1 Morphology and structure characterization · Fig. 1e; Fig. S4

In situ synchrotron radiation FTIR during ORR

Infrared spectroscopy

Cu-HHTP nanorod powder · Powder

BL01B at NSRL; homemade top-plate reflection infrared setup with ZnSe window; stability potential applied for 20 min before spectra; O2 continuously pumped; potentials from 0.8 to 0.46 V vs RHE.

Atmosphere: Continuous O2 saturation
Geometry: Top-plate cell reflection infrared setup with ZnSe window
Context: target pristine conductive MOF
Measurement source: 2 · 2.5 In situ SR-FTIR measurements · Fig. 4a-b; Fig. S24

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
C-O stretching band	about 1010 cm-1	—	—	Text Approximate	4 · 3.4 In situ SR-FTIR and EIS analysis · Fig. 4a; Fig. S24
C-O band shift under decreasing potential	shifts to high-wavelength direction by about 20 cm-1	—	—	Text Approximate	4 · 3.4 In situ SR-FTIR and EIS analysis · Fig. 4a-b
Cu-O stretching band	about 880 cm-1	—	—	Text Approximate	4 · 3.4 In situ SR-FTIR and EIS analysis · Fig. 4a; Fig. S24
Cu-OH shoulder band	about 920 cm-1	—	—	Text Approximate	4 · 3.4 In situ SR-FTIR and EIS analysis · Fig. 4a
*Surface H2O O-H stretching band**	about 3420 cm-1	—	—	Text Approximate	4 · 3.4 In situ SR-FTIR and EIS analysis · Fig. S24
*OOH intermediate bandMarked as a best value within this paper	about 1264 cm-1	—	—	Text Approximate	4 · 3.4 In situ SR-FTIR and EIS analysis · Fig. 4a

In situ Cu K-edge XAFS during ORR

Cu-HHTP nanorod powder · Powder

1W1B station, Beijing Synchrotron Radiation Facility; storage ring 2.5 GeV, 250 mA; Cu-HHTP distributed on carbon cloth after about 40 min sonication; O2-saturated 0.1 M KOH; potentials from 0.8 to 0.46 V vs RHE in main text and 0.96 to 0.46 V vs RHE in SI; fluorescence mode; fitted parameters in Table S4.

Atmosphere: O2-saturated alkaline electrolyte
Geometry: Homemade in situ electrochemical XAFS cell; carbon cloth support
Context: target pristine conductive MOF
Measurement source: 2 · 2.4 In situ XAFS measurements · Fig. 3; Table S4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Cu-O bond length at 0.46 VMarked as a best value within this paper	1.91(+/-0.02) A at 0.46 V vs RHE	—	+/-0.02 A	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O bond length at 0.66 V	1.92(+/-0.01) A at 0.66 V vs RHE	—	+/-0.01 A	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O bond length under potential-free state	1.93(+/-0.01) A under potential-free state	—	+/-0.01 A	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O coordination number at 0.46 VMarked as a best value within this paper	4.8(+/-0.1) at 0.46 V vs RHE	—	+/-0.1	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O coordination number at 0.66 V	4.5(+/-0.1) at 0.66 V vs RHE	—	+/-0.1	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O coordination number under potential-free state	4.0(+/-0.1)	—	+/-0.1	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O energy shift at 0.46 V vs RHE	5.5(+/-0.2) eV	—	+/-0.2 eV	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O energy shift at 0.66 V vs RHE	5.3(+/-0.2) eV	—	+/-0.2 eV	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O energy shift at potential-free state	5.4(+/-0.3) eV	—	+/-0.3 eV	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O EXAFS R-factor at 0.46 V vs RHE	0.009	—	—	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O EXAFS R-factor at 0.66 V vs RHE	0.007	—	—	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O EXAFS R-factor at potential-free state	0.008	—	—	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O Debye-Waller factor at 0.46 V vs RHE	6.8(+/-0.1) x 10^-3 A^2	—	+/-0.1 x 10^-3 A^2	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O Debye-Waller factor at 0.66 V vs RHE	6.5(+/-0.1) x 10^-3 A^2	—	+/-0.1 x 10^-3 A^2	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu-O Debye-Waller factor at potential-free state	6.4(+/-0.2) x 10^-3 A^2	—	+/-0.2 x 10^-3 A^2	SI Table Exact Reported	S29 · Supporting Tables · Table S4
Cu K-edge white-line trend	white-line intensity decreases as applied potential decreases	—	—	Text Qualitative	4 · 3.3 In situ XAFS study of Cu-HHTP · Fig. 3a

Cu 2p X-ray photoelectron spectroscopy (XPS)

X-ray photoelectron spectroscopy

Cu-HHTP nanorod powder · Powder

ESCALAB MKII XPS with Mg Kalpha excitation, hnu = 1253.6 eV.

Geometry: Powder surface spectroscopy
Context: target pristine conductive MOF
Measurement source: 3 · 3.1 Morphology and structure characterization · Fig. 1d

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Cu 2p3/2 Cu+ peak	about 934.8 eV	—	—	Text Approximate	3 · 3.1 Morphology and structure characterization · Fig. 1d
Cu2+/Cu+ ratio	2.14:1	—	—	Text Exact Reported	3 · 3.1 Morphology and structure characterization · Fig. 1d
Cu 2p3/2 Cu2+ peak	about 933 eV	—	—	Text Approximate	3 · 3.1 Morphology and structure characterization · Fig. 1d