Investigation on synthesis and characterization of Fe-doped Al₂O₃ nanocrystals by new sol–gel precursors

Synthesis and characterisation of Al2O3 nanoparticles as catalyst prepared by polymer co-precipitation method

“…With increasing temperature the mean particle size decreases from 26 nm to 10 nm because of PVP surfactant. [38][39][40][41][42][43][44][45][46][47] Figure 3 TEM analysis was carried out to confirm the actual size of the particles, their growth pattern and the distribution of the crystallites. Figure 5 shows the assynthesized TEM image of sphere-like shaped of Al 2 O 3 nanoparticles prepared by precipitation route.…”

Chromaticity coordinate vector principle for charge-transfer-type thermochromic material design: case of Fe/Cr-(co)doped α-Al2O3host

“…3(a)) can be ascribed to the three E u band vibrations from the contribution of the transverse/longitudinal optical (TO/LO) branches, respectively. 66,67 The as-noted v 12 and v 14 peaks in the FT-IR spectra are the E u modes in the transverse optical branch for the lattice vibration of α-Al 2 O 3 , 68,69 while the v 13 (592–579 cm −1 ) and v 16 (888–883 cm −1 ) peaks are ascribed to the transverse and longitudinal optical branch phonon mode frequencies of the A 2u mode, respectively. 66 We noted that nearly all the phonon modes shifted to a lower frequency with an increase in the doping level of Fe in the Al 2 O 3 lattice (Table S3, ESI†), which can be ascribed to the heavier Fe 3+ occupying the same crystallographic site of Al 3+ in the corundum structure, causing the vibrations for the same mode to appear at a lower frequency.…”

Dry Reforming of Methane for Hydrogen Production Using Bimetallic Catalysts of Pt‐Fe Supported on γ‐Alumina

“…The Al−O vibrations in the AlO 6 octahedra and AlO 4 tetrahedra were characterized by vibrational frequencies in the ranges of 500–700 and 700–900 cm −1 (Figure 6a), respectively [40] . The bands around 573 and 843 cm −1 (Figure 6b) confirmed that the increase of calcination temperature (1273 K), [25] who were subjected the catalysts favored the presence of these bands that became more intensive with a shift towards slightly lower wavenumber on compared with the catalysts calcinated at 773 K.…”