Silica-PO3H is widely used in chromatography as a stationary phase due to its strong ion-exchange properties. It is particularly effective in separating and purifying biomolecules like proteins, peptides, and nucleic acids. The phosphonic acid groups on the silica surface enable selective interactions with positively charged molecules, making it valuable in analytical and preparative chromatography. Additionally, it is employed in water treatment processes to remove heavy metal ions, leveraging its high affinity for cations. Its stability and functional group density also make it a useful material in catalysis and as a support for immobilizing enzymes in industrial applications.