The Formation Process of Hydroxyapatite Nanoparticles by Electrolysis and Their Physical Characteristics

The electrolysis method for synthesizing hydroxyapatite nanoparticles (NPs) has the advantage of controlling the particle size by adjusting the potential and current used. This study aims to study the electrolysis of hydroxyapatite NPs formation and its characteristics. The solution contained Na2H2EDTA.2H2O, KH2PO4, and CaCl2, with an EDTA/PO4^3-/Ca²⁺ concentration of 0.2/0.2/0.2 M. The electrolytic potential are 4, 5, and 6 volts for 6 hours. The carbon electrode spacing used is 2 cm. The precipitate formed is filtered with a vacuum jet ejector. Retentate was washed with demineralized water and dried in an oven at 105°C. The synthesis of pure hydroxyapatite by electrolysis was successfully carried out at a potential of 5 volts. The OH^- ion, which comes from the H2O reduction process at the cathode, is essential in the formation of brushite, which then forms hydroxyapatite. The hydroxyapatite, synthesized at a potential of 4 volts, had the smallest particle size (442.4 nm) with the largest particle surface area (417.22 m²/gram).