PEG-assisted room-temperature mechanochemical synthesis of silver–semiconductor composites with rich heterojunction for visible-light degradation of oxytetracycline

The room-temperature mechanochemical synthesis method was employed to fabricate the AgCl@Ag-NPs and AgCl@AgNPs/TiO 2 composite photocatalysts efficiently. The polyethylene glycol 400 was introduced to adjust the microstructure and layout of nanoparticles to form a large number of heterojunctions or even heterojunction chains between Ag-NPs and AgCl/TiO 2 . The surface plasmon resonance effect of metallic silver nanoparticle extends the absorption spectrum of composite to the visible region. And the metal–semiconductor heterojunction configuration enables the effective separation of electron–hole pairs to endow them strong catalytic activity for degradation of oxytetracycline under man-made natural light irradiation and, meanwhile, suppresses the bleaching of AgCl to give them good microstructural stability and photocatalytic reusability. In the process of photodegradation of oxytetracycline, AgCl@AgNPs/TiO 2 showed the higher catalytic efficiency through fuller synergy compared to AgCl@AgNPs. This work lays out a green degradation strategy for antibiotics in the ecological environment. Graphical abstract