[Bi6O4.5(OH)3.5]2(NO3)11: a new anhydrous bismuth basic nitrate. Synthesis and structure determination from twinned crystals

Dimorphism of [Bi2O2(OH)](NO3) - the ordered Pna21 structure at 100 K

The re-investigation of [Bi2O2(OH)](NO3), dioxidodibismuth(III) hydroxide nitrate, on the basis of single-crystal X-ray diffraction data revealed an apparent structural phase transition of a crystal structure determined previously (space group Cmc21 at 173 K) to a crystal structure with lower symmetry (space group Pna21 at 100 K). The Cmc21 → Pna21 group-subgroup relationship between the two crystal structures is klassengleiche with index 2. In contrast to the crystal structure in Cmc21 with orientational disorder of the nitrate anion, disorder does not occur in the Pna21 structure. Apart from the disorder of the nitrate anion, the general structural set-up in the two crystal structures is very similar: [Bi2O2]2+ layers extend parallel to (001) and alternate with layers of (OH)- anions above and (NO3)- anions below the cationic layer. Whereas the (OH)- anion shows strong bonds to the BiIII cations, the (NO3)- anion weakly binds to the BiIII cations of the cationic layer. A rather weak O-H⋯O hydrogen-bonding inter-action between the (OH)- anion and the (NO3)- anion links adjacent sheets along [001].

Single Unit-Cell Layered Bi2 Fe4 O9 Nanosheets: Synthesis, Formation Mechanism, and Anisotropic Thermal Expansion

As an important multiferroic material, pure and low-dimensional phase-stable bismuth ferrite has wide applications. Herein, one-pot hydrothermal method was used to synthesize bismuth ferrite. Almost pure Bi₂ Fe₄ O₉ , BiFeO₃ , and their mixture were successfully obtained by controlling the KOH concentration in the hydrothermal solutions. The as-prepared Bi₂ Fe₄ O₉ products were crystalline with Pbam space group, had nanosheet morphology, and tended to aggregate into nanofloret or random stacking. Each Bi₂ Fe₄ O₉ nanosheet was a single crystal with (001) plane as its exposed surface. Single unit-cell layered Bi₂ Fe₄ O₉ nanosheets had a uniform thickness of 1 nm. The surface energies of various (100), (010), and (001) planes were 3.6-4.0, 5.6-15.1, and 1.7-3.0 J m^-2 , respectively, in the Bi₂ Fe₄ O₉ crystal. The formation mechanism and structural model of the as-prepared single unit-cell layered Bi₂ Fe₄ O₉ nanosheets have been given. The growth of Bi₂ Fe₄ O₉ nanosheets was discussed. Thermal analysis showed that the Bi₂ Fe₄ O₉ phase was stable up to 1260 K. The thermal expansion behavior of the Bi₂ Fe₄ O₉ nanosheet was nonlinear. The thermal expansion coefficients of the ultrathin Bi₂ Fe₄ O₉ nanosheets on the a-, b-, c-axes, and on the unit-cell volume V were determined, showing an anisotropic thermal expansion behavior. This study is helpful for the controllable synthesis of ultrathin Bi₂ Fe₄ O₉ nanosheets.

Cerium-Bismuth Oxides/Oxynitrates with Low Toxicity for the Removal and Degradation of Organophosphates and Bisphenols

Nanoscale cerium-bismuth oxides/oxynitrates were prepared by a scalable low-temperature method at ambient pressure using water as the sole solvent. Solid solutions were formed up to a 1:1 Ce/Bi molar ratio, while at higher doping levels, bismuth oxynitrate photocatalysts with a pronounced layered structure were formed. Bismuth caused significant changes in the structure and surface properties of nanoceria, such as the formation of defects, oxygen-containing surface groups, and Lewis and Brønsted acid sites. The prepared bifunctional adsorbents/photocatalysts were efficient in the removal of toxic organophosphate (methyl paraoxon) from water by reactive adsorption followed by photocatalytic decomposition of the parent compound and its degradation product (p-nitrophenol). Bi-doped ceria also effectively adsorbed and photodegraded the endocrine disruptors bisphenols A and S and outperformed pure ceria and the P25 photocatalyst in terms of efficiency, durability, and long-term stability. The very low toxicity of Bi-nanoceria to mammalian cells, aquatic organisms, and bacteria has been demonstrated by comprehensive in vivo/in vitro testing, which, in addition to its simple "green" synthesis, high activity, and durability, makes Bi-doped ceria promising for safe use in abatement of toxic chemicals.

Synthesis of Ag/AgCl modified anhydrous basic bismuth nitrate from BiOCl and the antibacterial activity

Novel nanocomposite of Ag/AgCl and a single phase of anhydrous basic bismuth nitrate (ABBN)-Bi₆O_4.46(OH)_3.54(NO₃)_5.54 with efficient antibacterial activity was prepared from BiOCl. Microstructure was characterized as AgCl nanotubes and Ag nanoparticles mixed with Bi₆O_4.46(OH)_3.54(NO₃)_5.54 nanosheets in nanometer scale. Antibacterial activity of the composite was tested by agar disc diffusion and agar dilution methods using Escherichia coli as target bacteria. The diameter of inhibition zone of Ag/AgCl/ABBN is 17.0 mm while that of bulk BBN is 8.1 mm. The MIC value of Ag/AgCl/ABBN is ascertained as 35 μg mL^-1. Results prove that Ag/AgCl/ABBN nanocomposite has much higher antibacterial activity in comparison with bulk basic bismuth nitrate.

Anionic Bismuth-Oxido Carboxylate Clusters with Transition Metal Countercations

Six new anionic bismuth-oxido clusters containing trifluoroacetate ligands were prepared. These include two new Bi₆O₈ clusters: [M(NCMe)₂(H₂O)₄]₃[Bi₆(μ₃-O)₄(μ₃-OH)₄(CF₃CO₂)₁₂] with an octahedral Bi₆O₄(OH)₄ core (M = Ni, 1a; Co, 1b) and four Bi₄O₂ clusters, {[Co(NCMe)₆][Bi₄(μ₃-O)₂(CF₃CO₂)₁₀]}_n (2a), {[Co{HC(MeCO)₂(MeCNH)}₂][Bi₄(μ₃-O)₂(CF₃CO₂)₁₀]·2[CF₃CO₂]·2[CF₃CO₂H]·2[H₂O]}_n (2b), {[Cu(NCMe)₄]₂[Bi₄(μ₃-O)₂(CF₃CO₂)₁₀]·2[CF₃CO₂H]}_n (2c), and {[Me₄N]₂[Bi₄(μ₃-O)₂(CF₃CO₂)₁₀]·2[CF₃CO₂H]}_n (2d). These are among the first bismuth-oxido anionic clusters synthesized, and the first to have transition metal countercations. The Bi₆O₈ anion in 1a and 1b is a high-symmetry octahedron. Additionally, two of the new Bi₄O₂ clusters are arranged in 1D polymeric structures via bridging carboxylate ligands. The cation in compound 2c had not been previously characterized and was also observed in the synthesis of [Co{HC(MeCO)₂(MeCNH)}₂][Bi(NO₃)₆] (3). The new compounds were characterized using single crystal X-ray crystallography and elemental analysis.

Measurements and Modeling To Determine the Reduction Potential of Uncomplexed Bi(III) in Nitrate Solutions for Application in Bi(III)-Ligand Equilibria Studies by Voltammetry

The free metal ion potential, E(M), is a critical parameter in the calculation of formation constants when using voltammetry. When studying complex formation of Bi(III), however, E(Bi) cannot be directly measured. In this work a nitrate background electrolyte was employed to obtain reversible reduction waves. To determine E(Bi), measurements have to be made below pH ∼ 2 before the bismuth-oxy-nitrate species precipitates and thus corrections for the diffusion junction potential (monitored using Tl(I) as an internal reference ion) must be made. Additionally shifts in potential due to both Bi(III) hydrolysis and Bi(III) nitrate formation must also be compensated for before E(Bi) can be evaluated. The value of E(Bi) was determined relative to E(Tl) so that in an experiments where ligand is added to determine formation constants, E(Bi) can be determined as accurately as possible (since E(Tl) can generally still be measured). The value of E(Bi) - E(Tl) was found to be 495.6 ± 1.4 mV for the conditions employed.

Rapid and high-capacity adsorption of sulfonated anionic dyes onto basic bismuth(iii) nitrate via bidentate bridging and electrostatic attracting interactions

Rapid and high-capacity adsorption of sulfonated anionic dyes onto basic bismuth(iii) nitrate via bidentate bridging and electrostatic attractive interactions.

A {110} facet predominated Bi6O6(OH)3(NO3)3·1.5H2O photocatalyst: selective hydrothermal synthesis and its superior photocatalytic activity for degradation of phenol

A Bi₆O₆(OH)₃(NO₃)₃·1.5H₂O photocatalyst with predominant {110} facets but a low BET surface area was selectively prepared. It exhibits high photocatalytic activities for degradation of phenol.

Bi3+/M2+ Oxyphosphate: A Continuous Series of Polycationic Species from the 1D Single Chain to the 2D Planes. Part 2: Crystal Structure of Three Original Structural Types Showing a Combination of New Ribbonlike Polycations

With the assistance of structural models deduced from the high-resolution electron microscope (HREM) investigation presented in Part 1 of this work, three new structural types were pointed out in Bi2O3-MO-P2O5 ternary systems. Their crystal structures are built on the arrangement of 2D polycationic ribbons formed of edge-sharing O(Bi,M)4 tetrahedra and isolated by PO4 groups. Prior to this study, materials with ribbons up to n = 3 tetrahedra wide have been discovered. The original structures presented here display longer n = 4-6 cases, which suggests a possible continuous series of polycationic entities that range from the single chain (one tetrahedron wide) to the infinite [Bi2O2]2+ Aurivillius layer. The ribbons with n > 3 show strong structural modifications that are able to bring a good ribbon-phosphate cohesion. In addition to these fascinating structural results, this work fully confirms the validity of the decoding established from HREM images of a single crystallite in inhomogeneous mixtures.

Solvolytic routes to new nonabismuth hydroxy- and alkoxy-oxo complexes: synthesis, characterization and solid-state structures of novel nonabismuth polyoxo cations Bi9(µ3-O)8(µ3-OR)65+(R = H, Et)

Base hydrolysis of BiO(ClO4) yields ClO4- salts of the novel nonabismuth polyoxo cation Bi9(mu3-O)8(mu3-OH)6(5+); ethanolysis converts to the ethoxide Bi9(mu3-O)8(mu3-OEt)6(5+).