Hydroxyapatite/N-doped carbon dots/Ag3PO4 composite for improved visible-light photocatalytic performance

Abstract

In this study, a new hydroxyapatite/N-doped carbon dots/Ag₃PO₄ (HA/N-CDs/Ag₃PO₄) composite was prepared by a facile hydrothermal approach and in situ ion-exchange reaction method. The photocatalytic performance of the as-prepared samples was investigated by the degradation of methylene blue (MB) under visible light irradiation. It was found that the HA/N-CDs/Ag₃PO₄ composite exhibited much higher photocatalytic activity and stability compared with HA/N-CDs and HA/Ag₃PO₄. In addition, the effect of the amount of silver loading on the photocatalytic activity of the composite was evaluated. The experimental results showed that a higher silver loading amount led to a decrease of both the UV-Vis absorption and photocatalytic performance. A suitable content of silver loading produced the highest photocatalytic activity. The substantial improvement in the photocatalytic performance of the composite can be attributed to the synergetic effects of HA support, CDs and the formed Ag₃PO₄, which led to an increase of active sites, suppression of the electron–hole recombination, and the stability improvement of Ag₃PO₄. The HA/N-CDs/Ag₃PO₄ photocatalyst synthesized via a cost-effective route is a promising candidate in organics removal.