Sol‐Gel Synthesis and Characterization of Cubic Bismuth Zinc Niobium Oxide Nanopowders

Abstract

Bismuth zinc niobium oxide (BZN) was successfully synthesized by a diol-based sol-gel reaction utilizing metal acetate and alkoxide precursors. Thermal analysis of a liquid suspension of precursors suggests that the majority of organic precursors decompose at temperatures up to 150 ∘ C, and organic free powders form above 350 ∘ C. The experimental results indicate that a homogeneous gel is obtained at about 200 ∘ C and then converts to a mixture of intermediate oxides at 350-400 ∘ C. Finally, single-phased BZN powders are obtained between 500 and 900 ∘ C. The degree of chemical homogeneity as determined by X-ray diffraction and EDS mapping is consistent throughout the samples. Elemental analysis indicates that the atomic ratio of metals closely matches a Bi 1.5 ZnNb 1.5 O 7 composition. Crystallite sizes of the BZN powders calculated from the Scherrer equation are about 33-98 nm for the samples prepared at 500-700 ∘ C, respectively. The particle and crystallite sizes increase with increased sintering temperature. The estimated band gap of the BZN nanopowders from optical analysis is about 2.60-2.75 eV at 500-600 ∘ C. The observed phase formations and measured results in this study were compared with those of previous reports.

Electronic Structure Studies and Photocatalytic Properties of Cubic Bi1.5ZnNb1.5O7

“…The BZN compounds used as the catalyst in the experiments have been prepared by two different methods, a conventional solid-state reaction and a sol-gel technique. The synthesis of the cubic BZN powders at various temperatures by the sol-gel method has been described in detail in a previous report [36]. In the case of the solid-state method, the BZN powders have been prepared from high purity (99.9%) bismuth oxide (Bi 2 O 3 ), niobium oxide (Nb 2 O 5 ), and zinc oxide (ZnO), which have also been purchased from Aldrich (Australia).…”

Structure, thermal stability, optoelectronic and electrophysical properties of Mg- and Na-codoped bismuth niobate pyrochlores: Experimental and theoretical study

“…Besides, the substituted bismuth niobates can be used as low-temperature ceramic capacitors (LTCC) applicable in decoupling capacitors, wireless communications, and low-fire high-frequency filters through chemical compatibility with the metal electrodes (Ag, Cu) during co-firing. The Zn-or Mg-doped bismuth niobates can be formed by wet chemical synthesis at temperatures slightly above 500 °C, meanwhile sintering temperatures vary in the range of 850-900 °C [20,21,41]. One of the main drawbacks of wet synthesis is the high cost of the precursors and rather low yield of products.…”

Synthesis, Characterization, and Electronic Structure Studies of Cubic Bi1.5ZnTa1.5O7for Photocatalytic Applications

“…These starting materials have been used according to the required stoichiometric ratio to prepare cubic BZT with Bi 1.5 ZnTa 1.5 O 7 composition. The details of synthesis process have been described in our previous publication [12].…”