Optimizing the synthesis procedure and characterization of terbium(III) tungstate nanoparticles as high performance photocatalysts

Optimizing the synthesis of terbium(III) molybdate nanoplates through an orthogonal array design

“…The FTIR spectrum obtained for the sample prior to annealing (Figure a), contains several wide absorption peaks about 600, 830, 945, 1626, and 3370 cm −1 . The peaks at 3370 and 1626 cm −1 were attributed to the stretching and bending vibrations of the OH and HOH bonds present in the surface‐absorbed water, respectively . Upon heating the sample at 400 °C and further at 700 °C, the intensities of these peaks were dropped and several split absorption peaks were appeared, which is a clue supporting the argument about surface‐adsorbed water, whereas the stretching modes (υ 1 and υ 3 ) of Tb 2 (MoO 4 ) 3 with the tetragonal structure were appeared at the range of 620–1000 cm −1 .…”

“…The absorption peaks appeared in FTIR spectrum at 970 and 860 cm −1 are corresponding to the symmetric stretching of υ 1 mode of MoO bonds in the molybdate tetrahedron. The appeared broad bands at 732 and 805 cm −1 are attributed to υ 3 internal mode which are responsible for the asymmetric stretching vibrations of MoOMo bonds in the structure of MoO 4 .…”

“…FT-IR spectra of Tb 2 (MoO 4 ) 3 samples both before and after annealing at various temperatures are presented in Figure 5a. The FTIR spectrum obtained for the sample prior to annealing [13,44,45]. Upon heating the sample at 400 C and further at 700 C, the intensities of these peaks were dropped and several split absorption peaks were appeared, which is a clue supporting the argument about surface-adsorbed water, whereas the stretching modes (υ 1 and υ 3 ) of Tb 2 (MoO 4 ) 3 with the tetragonal structure were appeared at the range of 620-1000 cm −1 [13].…”

“…The absorption peaks appeared in FTIR spectrum at 970 and 860 cm −1 are corresponding to the symmetric stretching of υ 1 mode of Mo O bonds in the molybdate tetrahedron. The appeared broad bands at 732 and 805 cm −1 are attributed to υ 3 internal mode which are responsible for the asymmetric stretching vibrations of Mo O Mo bonds in the structure of MoO 4 [13,44,45]. The UV-Vis DRS of the sample is presented in Figure 6a,b contains Tauc's plot for the sample and accordingly the estimated band gap of the terbium molybdate nanoplates was determined to be around 3.65 eV.…”

Synthesis and Supercapacitor Application of Cerium Tungstate Nanostructure

“…FTIR spectra of the product (Figure ) obtained for samples both before and after annealing at 800 °C were also obtained. Figure a (the untreated sample) contains three wide absorption bands at around 847.58, 1628.59 and 3445.16 cm −1 , while with the calcinated sample (Fiure 3b) these bands were weakened, indicating the evaporation of adsorbed water . The calcinated sample further contains band corresponding to the scheleete type structure between 950 and 460 cm −1 (950.0, 862.1, 738.2, 694.6, 481.1, 458.8, 417.2) …”