Used as a staining agent in electron microscopy to visualize biological specimens, particularly for negative staining of viruses, proteins, and macromolecular complexes. Its heavy metal content provides high electron density, enhancing contrast under the microscope. Also employed in analytical chemistry as a reagent for detecting and precipitating certain organic compounds, such as alkaloids and amines. Serves as a catalyst in some organic synthesis reactions due to its strong acidity and redox properties. Additionally, utilized in the preparation of nanomaterials and supported catalysts because of its stable heteropoly structure.