Z-scheme Ag3PO4@polyaniline core-shell nanocomposite with high visible light photocatalytic performance for Microcystis aeruginosa inactivation

The widespread occurrence of heavy cyanobacterial blooms has posed serious threats to aquatic ecosystem and human health. In this work, a novel Z-scheme Ag3PO4@PANI core–shell photocatalyst was synthesized by a chemisorption method for Microcystis aeruginosa (M. aeruginosa) inactivation. The crystal structure, morphology, chemical states, and optical properties of as-prepared samples were characterized by XRD, TEM, XPS, ATR-FTIR, NMR, UV–vis, and PL. Ag3PO4@PANI with 10 wt.% of PANI showed the best performance of photocatalytic algae removal with 99.2% chlorophyll a degradation under 3 h visible light irradiation and excellent photostability after repetitive three times cyclic experiments. Moreover, the changing conditions of M. aeruginosa physiological characteristics during photocatalytic process were investigated. Furthermore, quenching experiment results indicated that superoxide radicals (·O2−) and photoinduced hole (h+) were dominant reaction active species. Finally, the possible inactivation mechanism of M. aeruginosa was proposed. Overall, this study provides a new insight in the efficient removal of the algae pollutants in eutrophic water bodies using Z-scheme mechanism core–shell photocatalysts.