Structure and microwave dielectric properties of low-temperature sinterable A2.5VMoO8 (A = Mg, Zn) molybdovanadate ceramics

Temperature-Induced Conversion of 2D Vanadium-Doped MoSe2 Nanosheets to 1D V2MoO8 Rods: Enhanced Performance in Electrochemical Antibiotic Detection in Biological and Environmental Samples

“…In addition, the intensity of the E 1 2g mode is lower than the A 1g mode, indicating the presence of rich edge sites in the fabricated VMoSe 2 nanosheets. , After the calcination process, the Raman spectrum at 300 °C shows the vibrational modes of both VMoSe 2 and VMO materials. However, with the temperature increase to 400 °C, an additional vibrational mode was observed at 163.3 and 316.8 cm –1 , which is related to the VO 4 tetrahedra or the edge-sharing distorted MoO 6 of the V–O or O–Mo–O bond. , When the temperature was increased from 400 to 500 °C or 600 °C, the Raman active bonds of the Mo–Se changed completely to Mo–O, indicating the successful formation of V–Mo-based oxides. When the temperature was increased from 300 to 400 °C, new peaks appeared at 260.48 and 713 cm –1 , corresponding to the MO bending vibration and the vibration of the Mo–O 3 bridge bond of MoO 3 . , However, the peaks shifted to lower wavenumbers when the calcination temperature was increased, which could be due to the higher crystallinity of VMO.…”

“…In comparison, the sample at 500 °C exhibits several active Raman peaks at 134.1 cm –1 , 163.3 cm –1 , 251.4 cm –1 , and 296.5 cm –1 , which can be assigned to the bending and stretching vibration modes of V–O or MoO bonds. The peaks at 134.1 cm –1 , 163.3 cm –1 , and 251.4 cm –1 can be assigned to the edge-sharing distorted MoO 6 (O–Mo–O) octahedra . The peaks at 296.5 and 343.3 cm –1 can be assigned to the symmetric stretching vibrations of the V–O–V (VO 4 ) and O–Mo–O bonds, respectively. , The peak at 673 cm –1 belongs to the asymmetric V–O stretching vibration mode (B g symmetry).…”

“…The asymmetric stretching vibrations of Mo−O (MoO 4 ) at 826.6 cm −1 and a symmetric stretching of M�O−V (Mo/V)O 4 tetrahedra at 1002.4 cm −1 were also observed. 36 From these spectra, the V−Mo−O bonds are smaller than the obtained Mo−O bond length but longer than the V−O bond length, indicating that there are more valence states for Mo than for V in the fabricated VMO structure, which may lead to better electrochemical performance toward sensing. 39 A similar trend was also observed for the samples thermally treated at 600 °C.…”

“…The peaks at 134.1 cm −1 , 163.3 cm −1 , and 251.4 cm −1 can be assigned to the edge-sharing distorted MoO 6 (O−Mo− O) octahedra. 36 The peaks at 296.5 and 343.3 cm −1 can be assigned to the symmetric stretching vibrations of the V−O−V (VO 4 ) and O−Mo−O bonds, respectively. 37,38 The peak at 673 cm −1 belongs to the asymmetric V−O stretching vibration mode (B g symmetry).…”

“…However, with the temperature increase to 400 °C, an additional vibrational mode was observed at 163.3 and 316.8 cm −1 , which is related to the VO 4 tetrahedra or the edgesharing distorted MoO 6 of the V−O or O−Mo−O bond. 35,36 When the temperature was increased from 400 to 500 °C or 600 °C, the Raman active bonds of the Mo−Se changed completely to Mo−O, indicating the successful formation of V−Mo-based oxides. When the temperature was increased from 300 to 400 °C, new peaks appeared at 260.48 and 713 cm −1 , corresponding to the M�O bending vibration and the vibration of the Mo−O 3 bridge bond of MoO 3 .…”