Rietveld Refinement, Structural Characterization, and Methylene Blue Adsorption of the New Compound Ba0.54Na0.46Nb1.29W0.37O5

Abstract

Using the solid-state process, the new compound Ba0.54Na0.46Nb1.29W0.37O5 was effectively produced in a single crystalline phase. The material’s characteristics were determined by X-ray diffraction and Raman techniques. The Rietveld method was applied to refine the structural properties of this sample using X-ray diffraction data and derive the diffraction line profile. The cell parameters a = b = 12.37843 ± 0.02 and c = 3.93526 ± 0.02 were accustomed to crystallizing this compound in the tetragonal tungsten bronze (TTB) structure of the space group P4bm. Thanks to Raman measurements, we were able to detect numerous vibration modes in this crystalline phase. The adsorption of methylene blue (MB) on crystalline phase was studied by UV–visible spectroscopy. On account of methylene blue adsorption on Ba0.54Na0.46Nb1.29W0.37O5, it was discovered that this material can be used to remove organic pollutants and thus be used for water treatment.

Crystallographic, Structural, and Electrical Properties of W6+ Substituted with Mo6+ in Crystalline Phases such as TTB Structure

“…The conventional solid-state technique was applied to synthesize the crystalline phases of the Ba 0.54 Na 0.46 Nb 1.29 W (0.37−x) Mo x O 5 system (x = 0.04, 0.08, and 0.33), as described in the experimental protocol for our previous work [44]. This experimental protocol for preparation of the crystalline phases within the NaNbO 3 -BaNb 2 O 6 -WO 3 /MoO 3 system involves two steps.…”

“…To ensure the secondary phase would be dependent on the BaMoO type, the dielectric properties of the current pieces were studied to see ho dielectric permittivity would change with increased BaMoO4 composite (see the d measurements section). The Rietveld refinement of the XRD patterns corresponding to the prepared ceramics of Ba 0.54 Na 0.46 Nb 1.29 W (0.37−x) Mo x O 5 (x = 0.04, 0.08, and 0.33) was fitted with a tetragonal (P4bm) model developed from the model of the previous crystalline phase [44]. Starting where x = 0.04, the Ba 2+ and Na + cations occupied two sites in this developed model.…”

“…The crystallographic parameters of the refined compositions (x = 0.04, 0.08, and 0.33) revealed that oxygen atoms surrounded sodium and barium atoms, creating deformed and irregular surroundings. The average distance between the sodium (1) and barium (1) atoms and the oxygen atoms was approximately 2.71 Å (x = 0.00)-2.88 Å (x = 0.33) [44]. Figure 2 illustrates the [1 1 1] projection of the crystal structure where x = 0.33.…”

“…It is worth noting that an average of 15 oxygen atoms enclosed the barium (2) and sodium (2) atoms, with the distance varying from 3.02 Å (0.00) to 2.74 Å (x = 33). Nonetheless, there was a slight distinction in the atomic positions of the Ba (2) and Na (2) atoms, as shown in Table 2 [44]. The Nb(1), Mo(1), or W(1) atoms were surrounded by six oxygen atoms, forming octahedrons that were linked together at their tips.…”

“…As shown in Figure 3, the Raman spectra were recorded between 1200 and 100 cm −1 of these prepared ceramics, characterized by different bands. The identification of these bonds with their bands has been made (see the Table 4) in reference to our previous work focused on crystalline phases (x = 0.0) [44].…”