Lattice vibrations of manganese oxides

FTIR Spectroscopic Study of Biogenic Mn-Oxide Formation byPseudomonas putidaGB-1

“…The spectral subtraction of GB-1 from GB-1/MnO x gives the difference spectrum of biogenic MnO x shown in Figure 5. This spectrum, which shows Mn-O vibrations at 349, 323, 302, and 271 cm −1 (Julien et al 2004) is comparable, but not identical to, that of acid birnessite (shown for comparision in Figure 5) that was synthesized abiotically in the laboratory according the method of McKenzie (1971).…”

“…Then 100 µL of sample was transferred onto IR transmission windows (ZnSe, CdTe, or Ge) and dried under vacuum (340 mbar) overnight. The accessible wavenumber ranges for ZnSe, CdTe, and Ge windows are 20,000 to 454 cm −1 , 20,000 to 360 cm −1 , and 5500 to 475 cm −1 respectively; with the CdTe crystal being more effective for data collection in the Mn-O stretching region (750 to 200 cm −1 ; Julien et al 2004). Transmission spectra were collected with a minimum of 400 scans at a 4 cm −1 resolution.…”

“…The main difference between GB-1 and GB-1/MnO x is observed on the CdTe window, with peaks at 431, 418, 408, 399, 377, and 369 cm −1 , corresponding to IR absorbances of MnO x (Julien et al 2004). Unlike ZnSe, the use of CdTe crystals allows spectra to be collected to low wavenumbers (i.e., 360 cm −1 ) where Mn-O stretching occurs.…”

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

“…From Mn-O stretching range, the two sharp, high-intensity, high-frequency Raman bands at 544 and 607 cm -1 are indicative of a well-developed tetragonal structure with an interstitial space consisting of (2 9 2) tunnels of cryptomelane material [21,22].…”

ORR Electrocatalysis on Cr3+, Fe2+, Co2+-Doped Manganese(IV) Oxides

“…2a). The stretching mode of MnO 6 octahedrons along the double-chain is located at 708 cm −1 in the FTIR spectra of sample 2 with hollandite structure [44]. Sample 2 has relatively sharp peaks indicative of a well-developed hollandite-type α-MnO 2 structure with an interstitial space consisting of narrow one-dimensional (2 × 2) channels.…”