Synthesis and visible-light photocatalytic degradation of Ag3PO4/AgBr/hydroxyapatite ternary nanocomposites prepared from oyster shells

Abstract

In this paper, a new type of Ag₃PO₄/AgBr/hydroxyapatite (HAP) composite was successfully prepared from oyster shells and silver nitrate by a hydrothermal method. The samples were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, electron spin resonance and other precision instruments, and their catalytic activity was characterized by visible light degradation of methylene blue (MB). The experimental results show that the Ag₃PO₄/AgBr/HAP photocatalyst has a nanoscale rod-like structure and excellent photodegradation performance. Although the content of Ag₃PO₄ or AgBr had a significant effect on the reaction activity, the effects did not all positively correlate, and only the appropriate ratio could produce an improved catalytic effect. The catalytic performance of the 1:1-Ag₃PO₄/AgBr/HAP composite was the best: complete degradation of MB was achieved within 40 min, and the reaction rate was 15 times that of Ag₃PO₄/AgBr. In the process of photocatalytic degradation, ˙O²⁻ and h⁺ are the main active species involved in the reaction, and the synergistic catalysis of Ag₃PO₄, AgBr and HAP promotes the degradation rate.