Insight into the investigation on nanostructured defect pyrochlore Bi2-xFexWO6 and its photocatalytic degradation of mixed cationic dyes

High-temperature stabilized defect pyrochlore Bi2−xFexWO6 nanostructures and their effects on photocatalytic water remediation and photo-electrochemical oxygen evolution kinetics

“…53 However, as the Fe concentration increases in the lattice of BWO, the absorbance range and intensity also increase. 44 From the literature, a tail-like formation in the absorbance edge can be attributed to the excess Fe ions forming a cluster around the BWO structures. 32 The direct band gap values were estimated using the Kubelka–Munk (KM) plot and eqn (5): F ( R ) is the KM function, R is the percentage of reflectance, and n = 2 for direct bandgap calculation.…”

“…However, with Fe inclusion, this new phase completely disappears, which is also consistent with our previous reports. 44 Herein, the reduction of the Bi precursor leads to a Bi-deficient environment, which could be a possibility for the disappearance of the Bi 14 W 2 O 27 phase. Additionally, as the Fe concentration increases, from X = 0.2 to 1.0, new minuscule peaks develop at 29.81°, 34.45°, and 49.54°.…”

“…Comparing our previous work, the XRD patterns of Bi 2−x Fe x -WO 6 NPs calcined at 600 °C displayed similar unknown peaks, substantiating this critical transition. 44,46 Still, in the case of calcination at 800 °C, the unknown peak formation is minimal, which can be associated with a higher calcination temperature. On continuing with the increase in Fe content, a structural transformation was detected for the nominal concentration of X = 1.5 (Bi 0.5 Fe 1.5 WO 6 ), and the diffraction patterns equivalent to X = 1.5 matched well with JCPDS 38-1289, showing a tetragonal crystal structure.…”

Pyrochlore phase in the Bi2O3-Fe2O3-WO3-(H2O) system: its stability field in the low-temperature region of the phase diagram and thermal stability

“…Phase equilibria in the Bi 2 O 3 -Fe 2 O 3 -WO 3 system have not previously been the subject of systematic research, since only a few works devoted to the synthesis and characterization of compounds formed in this system are found in the scientific literature [24][25][26]. In particular, pyrochlore-structured compounds of variable composition were for the first time obtained and structurally characterized in a recent work by the authors [27] in 2020; however, studies of their stability field localization, as well as their thermal stability, have not been carried out to date.…”

Pyrochlore phase in the Bi2O3-Fe2O3-WO3-(H2O) system: its formation by hydrothermal synthesis in the low-temperature region of the phase diagram

“…Currently, there is an increased interest in ternary and more multicomponent pyrochlores containing d-elements, since this class of complex oxides has a set of promising physicochemical properties, among which are magnetic [6][7][8], electrophysical [9,10], catalytic [11,12] and optical [13][14][15] ones. In most of the presented works, the pyrochlore phase is obtained by the solid-state synthesis [6][7][8][9][10][11]13], and only in some works, chemistry methods are used to obtain the pyrochlore phase, in particular, by the hydrothermal method [12,[14][15][16] or by co-precipitation followed by annealing [17,18]. Important advantages of the hydrothermal method are the possibility of obtaining nanocrystalline materials and synthesizing oxide phases that are unstable at elevated temperatures [19,20].…”