Facile synthesis and characterization of hydroxyapatite from fish bones: Photocatalytic degradation of industrial dyes (crystal violet and Congo red)

Abstract The major component of bone minerals is the nanosized hydroxyapatite (HAp). It is known to possess extreme and exceptional properties. HAp increases its application in biomedical purposes. The utilization of HAp is comparatively similar to the use of living bones due to the monolithic structures, bioactivity and biocompatibility. Based on the potential characteristics of HAp, the present research has aimed to synthesize HAp from the natural biowaste of fish bones as a source of calcium phosphate in the form of HAp. The synthesized fish bone hydroxyapatite (FB-HAp) was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), Field emission - scanning microscopy (FESEM), Transmission electron microscopy (TEM) and Thermo gravimetric analysis (TGA). To reveal the environmental application of FB-HAp, photocatalytic degradations of Crystal violet (CV) and Congo red (CR) were performed under direct sunlight irradiation. FB-HAp showed 77 % degradation of CV and 87 % of CR within 75 min of exposure. Therefore, the collective findings suggested that the HAp prepared using the biowastes of Catla fish bones would be a safer, non-toxic and potential candidate for the photodegradation of synthetic dyes used in textile industries.