Bismuth Oxide, Bismuth Trioxide, Bismuth Sesquioxide, 1304-76-3

Bismuth Oxide, Bismuth Trioxide, Bismuth Sesquioxide, 1304-76-3

🧪 Bismuth(III) Oxide (Bi₂O₃)

Bismuth(III) oxide, also known as Bismuth trioxide or Bismuth sesquioxide, is an important inorganic compound of bismuth and oxygen. It is widely used in ceramics, electronics, catalysts, and medical applications due to its high refractive index, ionic conductivity, and relative non-toxicity compared to other heavy metal oxides.

1️⃣ Chemical Identity

• Chemical Name: Bismuth(III) Oxide

• Formula: Bi₂O₃

• Molecular Weight: 465.96 g/mol

• CAS Number: 1304-76-3

• EC Number: 215-134-7

• Appearance: Yellow to orange crystalline powder

• Crystal Structure: Multiple polymorphs (α-monoclinic, β-tetragonal, γ-body-centered cubic, δ-cubic high-temperature phase)

• Density: ~8.9 g/cm³

• Melting Point: ~817 °C (α-phase)

• Solubility: Insoluble in water; soluble in acids

2️⃣ Physical & Chemical Properties

• Polymorphism: Exhibits several crystalline phases depending on temperature (α, β, γ, δ).

• Optical Properties: High refractive index, useful in optical coatings.

• Electrical Properties: δ-Bi₂O₃ phase shows high oxygen ion conductivity, applied in solid oxide fuel cells.

• Chemical Behavior: Stable in air; reacts with acids to form bismuth salts.

• Non-Toxicity: Considered less toxic compared to lead oxides, making it suitable for eco-friendly applications.

3️⃣ Applications

• Ceramics & Glass:

  • Used as a pigment and additive for high refractive index glasses.

  • Improves mechanical and optical properties of ceramics.

• Electronics:

  • Solid electrolytes in fuel cells (due to ionic conductivity of δ-phase).

  • Dielectric material in capacitors.

• Catalysis:

  • Catalyst in organic reactions (oxidations, selective transformations).

• Medical:

  • Component in dental materials and pharmaceuticals (antibacterial properties).

• Pigments:

  • Yellow-orange pigment in coatings and plastics.

4️⃣ Synonyms

• Bismuth Oxide

• Bismuth(III) Oxide

• Bismuth Trioxide

• Bismuth Sesquioxide

• Bi₂O₃

5️⃣ Safety & Handling

• Toxicity: Relatively low compared to other heavy metal oxides, but fine powders may irritate eyes and respiratory tract.

• Precautions: Gloves, goggles, and dust masks recommended.

• Storage: Keep in dry, sealed containers; protect from moisture.

• Waste Disposal: Follow local environmental regulations.

📌 Summary: Bismuth(III) Oxide (CAS 1304-76-3) is a versatile inorganic compound with optical, electronic, catalytic, and medical applications, valued for its high refractive index, ionic conductivity, and eco-friendly profile compared to other heavy metal oxides.