A Z-Scheme Polyimide/AgBr@Ag Aerogel with Excellent Photocatalytic Performance for the Degradation of Oxytetracycline.

A novel Z-scheme polyimide (PI)/AgBr@Ag aerogel photocatalyst has been successfully synthesized by combining an in situ precipitation method and a supercritical drying method. The as-prepared PI/AgBr@Ag-50 (50 wt % AgBr@Ag in PI/AgBr@Ag) aerogel photocatalyst exhibited excellent photocatalytic activity for oxytetracycline degradation with a rate constant of 0.025 min-1 , which was 6.9 and 2.6 times higher than that of the PI aerogel or the AgBr@Ag nanoparticles, respectively. More significantly, the PI/AgBr@Ag-50 aerogel photocatalyst showed stable cycling, which could be attributed to the high mechanical strength and 3D network of the PI aerogel. The introduction of AgBr@Ag on PI with a heterojunction structure efficiently promoted the separation of electron-hole pairs by a Z-scheme mechanism. The reduced metallic Ag nanoparticles were found to function as centers for the transfer of electrons from AgBr to PI. This work has revealed a new application for the aerogel PI/AgBr@Ag photocatalyst in environmental protection.