cMOF Evidence Base
Spectroscopy — Dielectric relaxation processes, electronic structure, and band gap engineering of MFU-4-type metal-organic frameworks: Towards a rational design of semiconducting microporous materials

Measurement evidence

Spectroscopy

Dielectric relaxation processes, electronic structure, and band gap engineering of MFU-4-type metal-organic frameworks: Towards a rational design of semiconducting microporous materials · Sippel P., Denysenko D., Loidl A. et al. · Advanced Functional Materials · 2014 · 3885-3896

2 measurement groups · 18 results

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

Diffuse reflectance UV/vis/NIR spectroscopy and Kubelka-Munk/Tauc analysis

UV-visible and optical absorption spectroscopy

Co-MFU-4 powder heated at 280 C under vacuum · Powder

Room-temperature diffuse reflectance spectra, 300-900 nm, Perkin Elmer lambda 750s spectrometer, Labsphere integrating sphere, Spectralon white standard.

Temperature
room temperature
Geometry
powder diffuse reflectance
Context
MFU-4 and Co-MFU-4 powder comparison
Measurement source
p011 · Experimental Section, Optical Spectroscopy · Fig. 9 / Fig. 10
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
Co-MFU-4 Co(II) absorption-band maximumapproximately 2.1 eV (= 600 nm)600 nmapproximatelyText
Approximate		p007 · Optical Band Gaps · Fig. 9
Co-MFU-4 high-energy optical band gap from Kubelka-Munk cut-off2.72 eV—interpretation-dependentText
Approximate		p007 · Optical Band Gaps · Fig. 9 / Fig. 10
Co-MFU-4 low-energy optical band gap from Kubelka-Munk cut-off1.84 eV—allowing to estimateText
Approximate		p006 · Optical Band Gaps · Fig. 9
Co-MFU-4 high-energy/intrinsic Tauc optical band gapabout 2.86 eV—about; assignment-dependentText
Rounded Reported		p007 · Optical Band Gaps · Fig. 10
Co-MFU-4 low-energy Tauc optical band gapMarked as a best value within this paperabout 1.87 eV—about; assignment tentativeText
Rounded Reported		p007 · Optical Band Gaps · Fig. 10
MFU-4 optical band gap from Kubelka-Munk cut-off3.05 eV—allowing to estimateText
Approximate		p006 · Optical Band Gaps · Fig. 9
MFU-4 optical band gap range across Tauc exponents3.01-3.08 eV—rangeText
Range		p007 · Optical Band Gaps · Fig. 10
MFU-4 room-temperature Tauc optical band gapMarked as a best value within this paperabout 3.08 eV—aboutText
Rounded Reported		p007 · Optical Band Gaps · Fig. 10

Temperature-dependent diffuse reflectance UV-vis-NIR spectroscopy and Tauc analysis

UV-visible and optical absorption spectroscopy

Co-MFU-4 powder heated at 280 C under vacuum · Powder

850-350 nm under flowing nitrogen; samples kept 90 min at 120 C under N2 before gradual cooling; direct allowed Tauc plots.

Temperature
193, 243, 293, 343, 393
Atmosphere
flowing nitrogen
Geometry
powder diffuse reflectance in Harrick Praying Mantis reaction chamber
Context
MFU-4 and Co-MFU-4 powder comparison
Measurement source
p019 · Determination of the optical band gap · Fig. S19-Fig. S23 / Tables S2-S4
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
Co-MFU-4 high-energy optical band gap at 293 K2.864 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S3
Co-MFU-4 high-energy extrapolated optical band gap at 0 K2.90 eV—linear extrapolation; slightly overestimatedSI Table
Rounded Reported		p020 · Determination of the optical band gap · Table S4
Co-MFU-4 low-energy optical band gap at 293 KMarked as a best value within this paper1.880 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S3
Co-MFU-4 low-energy extrapolated optical band gap at 0 KMarked as a best value within this paper1.95 eV—linear extrapolation; slightly overestimatedSI Table
Rounded Reported		p020 · Determination of the optical band gap · Table S4
MFU-4 temperature-dependent optical band gap at 193 K3.120 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S2
MFU-4 temperature-dependent optical band gap at 243 K3.112 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S2
MFU-4 temperature-dependent optical band gap at 293 KMarked as a best value within this paper3.102 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S2
MFU-4 temperature-dependent optical band gap at 343 K3.090 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S2
MFU-4 temperature-dependent optical band gap at 393 K3.076 eV——SI Table
Exact Reported		p020 · Determination of the optical band gap · Table S2
MFU-4 extrapolated optical band gap at 0 KMarked as a best value within this paper3.16 eV—linear extrapolation; slightly overestimatedSI Table
Rounded Reported		p020 · Determination of the optical band gap · Table S4