Niobium Pentaoxide: Properties, Uses & FAQs

Niobium pentaoxide is a white, high-melting refractory oxide of niobium with the molecular formula Nb2O5, valued in research and industry for its dielectric, catalytic, and optical properties.

Molecular Formula

Nb2O5

Molecular Weight

265.81 g/mol

Melting Point

Approximately 1512 °C

Appearance

White crystalline powder

Density

Approximately 4.6 g/cm³

Solubility

Insoluble in water; soluble in hot concentrated HF and strong alkalis

CAS Number

1313-96-8

Chemical and Physical Properties

Niobium pentaoxide (Nb2O5, CAS 1313-96-8) is the most thermodynamically stable oxide of niobium. It is a white, odorless crystalline powder with a high melting point of approximately 1512 °C and a density of approximately 4.6 g/cm³. Nb2O5 is amphoteric in nature, behaving primarily as an acidic oxide: it is insoluble in water and most common acids but dissolves in hot concentrated hydrofluoric acid and strong alkali solutions. Upon heating, Nb2O5 can adopt several polymorphic crystalline phases (TT, T, M, N, and H phases), with the monoclinic (H-phase) being the high-temperature stable form. Its wide bandgap (~3.4 eV) and high refractive index make it optically significant.

Key Applications in Research and Industry

Nb2O5 is a versatile material employed across several high-technology fields:

• Dielectric Ceramics and Capacitors: Nb2O5 is a critical precursor for niobate-based ferroelectric and dielectric ceramics such as lithium niobate (LiNbO3) and potassium niobate, widely used in capacitors, piezoelectric devices, and optical waveguides.
• Catalysis: Owing to its surface acidity and redox properties, Nb2O5 serves as a catalyst or catalyst support for selective oxidation, dehydration, and esterification reactions.
• Optical Coatings: Its high refractive index (~2.3 in thin film form) and good transparency in the visible and near-IR range make Nb2O5 a preferred material for anti-reflection coatings, beam splitters, and optical interference filters.
• Solid-State Electrolytes and Batteries: Nb2O5 is investigated as an anode material in lithium-ion batteries due to its structural ability to accommodate Li+ ions through intercalation.
• Photocatalysis: The semiconductor band structure of Nb2O5 makes it active in UV-driven photocatalytic degradation of organic pollutants and water splitting research.

Safe Handling and Storage

Niobium pentaoxide is generally considered to have low acute toxicity, but standard laboratory precautions must be followed:

• Personal Protective Equipment (PPE): Wear nitrile gloves, a laboratory coat, and safety goggles when handling Nb2O5 powder to prevent skin, eye, and inhalation exposure to fine particulates.
• Ventilation: Handle the powder in a well-ventilated area or fume hood to minimize inhalation of airborne dust.
• Storage: Store in a tightly closed container in a cool, dry, well-ventilated area away from incompatible materials such as strong reducing agents and hydrofluoric acid. Nb2O5 is non-flammable and does not require special fire-hazard storage conditions.
• Disposal: Dispose of in accordance with local, regional, and national regulations for inorganic oxide waste.

Always consult the current Safety Data Sheet (SDS) before use.

Purity, Grades, and Quality Considerations

For research applications, the purity of Nb2O5 is a critical parameter that can significantly affect experimental outcomes, particularly in electronic ceramics, thin-film deposition, and catalytic studies. Common purity grades available from reagent suppliers range from technical grade to high-purity (≥99.9%) and ultra-high-purity (≥99.99%) grades. Key impurities to consider include tantalum (Ta), which is chemically similar to niobium and difficult to separate, as well as other transition metal oxides. Researchers requiring tight dielectric or optical specifications should confirm the Ta content and trace metal analysis with their supplier. Particle size and surface area can also vary between lots and may influence sintering behavior and catalytic activity. Request a Certificate of Analysis (CoA) for each lot to verify specifications before use.

Ordering Niobium Pentaoxide from Aladdin Scientific

Aladdin Scientific supplies Niobium pentaoxide under SKU N1539892. When placing your order, consider the following:

• Quantity: Select the pack size that suits your project timeline to minimize prolonged storage of opened containers.
• Documentation: A Certificate of Analysis (CoA) and Safety Data Sheet (SDS) are available upon request or through your account portal.
• Bulk Orders: For large-quantity or custom-specification requirements, contact our sales team to discuss pricing and lead times.
• Shipping: Nb2O5 is a non-hazardous solid for standard shipping purposes under most international regulations, but confirm local import requirements for inorganic chemicals before ordering.
• Returns: Refer to Aladdin Scientific's returns and refund policy for reagents; products must be returned in original, unopened packaging within the applicable return window.

Frequently asked questions

What is niobium pentaoxide used for in research?

Niobium pentaoxide (Nb2O5) is used as a precursor for ferroelectric and dielectric ceramics such as lithium niobate, as a catalyst or catalyst support for selective oxidation and esterification reactions, as an optical coating material due to its high refractive index, and as an electrode or anode material in lithium-ion battery research. It is also studied for photocatalytic applications in environmental remediation.

Is niobium pentaoxide soluble in water?

No, niobium pentaoxide is insoluble in water and in most common mineral acids. It dissolves in hot concentrated hydrofluoric acid (HF) and in strong alkali solutions. This chemical stability makes it suitable for high-temperature and chemically demanding applications.

What purity grades of Nb2O5 are available, and how do I choose the right one?

Nb2O5 is available in technical, high-purity (≥99.9%), and ultra-high-purity (≥99.99%) grades. For general synthetic chemistry, high-purity grades are typically sufficient. For optical coatings, advanced ceramics, or electronic applications where trace tantalum or other metal impurities could compromise device performance, ultra-high-purity grades are recommended. Always request a Certificate of Analysis (CoA) to confirm lot-specific data.

What safety precautions should I take when handling Nb2O5 powder?

Wear appropriate PPE including nitrile gloves, laboratory coat, and safety goggles to avoid skin and eye contact with the fine powder. Handle in a well-ventilated area or fume hood to prevent inhalation of dust. Although Nb2O5 has low acute toxicity, prolonged inhalation of any fine inorganic particulate should be avoided. Consult the current SDS for full hazard information before use.

How should I store niobium pentaoxide to maintain its quality?

Store Nb2O5 in a tightly sealed container in a cool, dry, and well-ventilated location away from moisture, strong reducing agents, and hydrofluoric acid. Keep the container closed when not in use to prevent moisture uptake or contamination. Under these conditions, Nb2O5 is stable for extended periods.

How can I order niobium pentaoxide from Aladdin Scientific?

Niobium pentaoxide is available from Aladdin Scientific under SKU N1539892. You can place your order directly through the Aladdin Scientific website. For bulk quantities, custom specifications, or questions about documentation such as CoA or SDS, please contact our customer service or sales team.

References

1. Nico, C., Monteiro, T., & Graça, M. P. F. (2016). Niobium oxides and niobates physical properties: Review and prospects. Progress in Materials Science, 80, 1–37. doi:10.1016/j.pmatsci.2016.02.001
2. Nowak, I., & Ziolek, M. (1999). Niobium Compounds: Preparation, Characterization, and Application in Heterogeneous Catalysis. Chemical Reviews, 99(12), 3603–3624. doi:10.1021/cr9800208
3. Griffith, K. J., Wiaderek, K. M., Cibin, G., Marbella, L. E., & Grey, C. P. (2018). Niobium tungsten oxides for high-rate lithium-ion energy storage. Nature, 559, 556–563. doi:10.1038/s41586-018-0347-0

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.