Biohybrid multifunctional Ag3PO4 loaded natural nano-hydroxyapatite from salmon bones for disposal of wastewater

Abstract

Even with the current advancement, the treatment of industrial and aquaculture wastewater containing organic and inorganic pollutants is still one of the research focuses, and the development of photocatalysts degrading those contaminants under visible light has been considered an essential strategy. In this study, we reported a novel multifunctional photocatalytic material (nHAP-Ag₃PO₄) composed of natural nano-hydroxyapatite (nHAP) from salmon processing by-products, fish bones, with an in-situ Ag₃PO₄ loading, by a body-centered cubic structure. Under visible light irradiation, with organic dyes, tetracycline (TC) and Pb(II) as simulated water pollutants, it was found that nHAP-Ag₃PO₄ had an excellent degradation rate for organic dyes and TC, reaching more significant than 95%, and stabilities towards them, for which the degradation rate remained higher than 83% after three cycles. Additionally, it exhibits efficient adsorption capability of heavy metal ions by adsorbing 180 mg/g for Pb(II) within 100 min, which is approximately three times that of pure nHAP. Furthermore, the nHAP-Ag₃PO₄ composite also possesses high-efficiency polyphenol oxidase (PPO) mimicking activity, compared with natural laccase, nHAP-Ag₃PO₄ possesses a similar substrate affinity and a higher reaction rate. This work provides a tremendous potential versatile material for future practical applications in the disposal of wastewater.

Graphical abstract

A novel nHAP-Ag₃PO₄ nanoparticle was constructed to improve the stability and dispersion of Ag₃PO₄, contributing to the excellent photodegradation ability of organic pollutants, good heavy metal adsorption ability and high PPO-like activity.