Porous hollow Ag/Ag2S/Ag3PO4 nanocomposites as highly efficient heterojunction photocatalysts for the removal of antibiotics under simulated sunlight irradiation.

Abstract

Antibiotic pollutants are a serious and growing threat to human health and the environment that efficient measures must be taken to eliminate them. Here, we report the facile fabrication of porous hollow Ag/Ag2S/Ag3PO4 heterostrucutres for efficient photocatalytic degradation of tetracycline under simulated sunlight irradiation. The morphology manipulation and hetero-nanocomposites construction through a coprecipitation-refluxing approach were applied to enhance the photocatalytic performance of the Ag/Ag2S/Ag3PO4 products. The photodegradation outcomes indicated that the heterojunction Ag/Ag2S/Ag3PO4 photocatalyst with a suitable band gap energy of 2.17\xa0eV, has better degradation performance (∼95%) than individual Ag2S and Ag3PO4 structures after 120\xa0min of simulated sunlight irradiation, even after five recycles. The good photocatalytic activity of Ag/Ag2S/Ag3PO4 nanocomposites could be mainly attributed to the unique hierarchical architectures, promoted visible-light harvesting, reduced a recombination and boosted separation of electron-hole pairs originated from the as-formed heterojunctions. Moreover, we proposed a photocatalytic degradation mechanism based on the radical scavenging results, which disclosed that the •O2- and •OH species perform essential tasks for the photodegradation of antibiotics by Ag/Ag2S/Ag3PO4 nanocomposites.