Synergistic effect of Au nanoparticles on hydroxyapatite support for photocatalytic degradation of organic pollutants in wastewater

Abstract

The efficient degradation of organic pollutants in wastewater is an important challenge and process a significant threat to ecosystems. The gold nanoparticles (AuNPs) performed well photocatalytic activity but suffered from the obvious agglomeration of nanoparticles and restriction in application. In this study, hydroxyapatite supports was synthesized for loading gold nanoparticles to enhance the dispersed distribution. The synergistic effect of AuNPs and HAP on photocatalysis degradation process were systematic study. The AuNPs were prepared by liquid phase reduction method and then supported on the HAP prepared by chemical precipitation method to form AuNPs/HAP composites photocatalyst. The prepared HAP support showed sufficient AuNPs supporting sites, with a high specific surface area of 17.25 m²/g and a lower porous size of 16.96 nm. The degradation experimental results showed that the AuNPs/HAP had high photocatalytic activity and superior recyclability. When the particle size of AuNPs was lower to 4.82 nm and the mass ratio of AuNPs was 0.5 wt%, the degradation rate of organic pollutants reached 89.9 % under irradiation for 60 min. The excellent characteristics of HAP as support and the fully dispersion of AuNPs with smaller particles size refrained from the particle agglomeration and enhanced the photocatalytic activity of composite photocatalyst.