Sustainable synthesis of nano-hydroxyapatite from chicken bones: Effect of microwave treatment on structural and electrochemical performance

Hydroxyapatite (HAp) is a bioactive calcium phosphate ceramic, which is the major inorganic constituent of natural teeth and bone. The current research paper involves the production of hydroxyapatite using chicken bone waste through a sustainable process and its pre- and post-processing with the use of microwave post-treatment. The originality of the work is the synthesis of a biogenic source of calcium with the irradiation of microwaves in order to adjust the structural and electrochemical characteristics of HAp. HAP1 was prepared as a sample by grinding and then by calcification, and then HAP2 was prepared by treating HAP1 with microwave. X-ray diffraction (XRD) ensured that the two samples are crystalline, and the microwave treatment caused slight changes in the peak and the size of crystallites. FESEM and TEM observations showed that HAP2 had smaller and more homogenous particles with lower agglomeration than HAP1. EDS identified the Ca, P, and O as the significant elements with minor traces of Mg and Na being biogenic in nature. Electrochemical characterization showed better ionic mobility, charge-transfer behavior, and capacitance of HAP1, but the treatment of microwave treatment raised the internal resistance and lowered ionic conductivity. In general, the research illustrates that microwave processing can increase the level of morphological homogeneity of biogenic HAp, but it has a comparable negative effect on the electrochemical activity.